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Contents of README:
MySQL Connector/J
Copyright 1997-2008 MySQL AB
This documentation is NOT distributed under a GPL license. Use of
this documentation is subject to the following terms: You may
create a printed copy of this documentation solely for your own
personal use. Conversion to other formats is allowed as long as
the actual content is not altered or edited in any way. You shall
not publish or distribute this documentation in any form or on any
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similar to how MySQL disseminates it (that is, electronically for
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similar medium, provided however that the documentation is
disseminated together with the software on the same medium. Any
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this documentation, in whole or in part, in another publication,
requires the prior written consent from an authorized
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to this documentation not expressly granted above.
For more information on the terms of this license, for details on
how the MySQL documentation is built and produced, or if you are
interested in doing a translation, please contact us at
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downloadable versions in variety of formats, including HTML, CHM
and PDF formats, see MySQL Documentation Library
(http://dev.mysql.com/doc).
Abstract
This manual describes MySQL Connector/J, the JDBC implementation
for communicating with MySQL servers.
Document generated on: 2008-03-01 (revision: 10086)
_______________________________________________________
MySQL Connector/J
MySQL provides connectivity for client applications developed in
the Java programming language via a JDBC driver, which is called
MySQL Connector/J.
MySQL Connector/J is a JDBC Type 4 driver. Different versions are
available that are compatible with the JDBC-3.0 and JDBC-4.0
specifications. The Type 4 designation means that the driver is
pure-Java implementation of the MySQL protocol and does not rely
on the MySQL client libraries.
Although JDBC is useful by itself, we would hope that if you are
not familiar with JDBC that after reading the first few sections
of this manual, that you would avoid using naked JDBC for all but
the most trivial problems and consider using one of the popular
persistence frameworks such as Hibernate
(http://www.hibernate.org/), Spring's JDBC templates
(http://www.springframework.org/) or Ibatis SQL Maps
(http://ibatis.apache.org/) to do the majority of repetitive work
and heavier lifting that is sometimes required with JDBC.
This section is not designed to be a complete JDBC tutorial. If
you need more information about using JDBC you might be interested
in the following online tutorials that are more in-depth than the
information presented here:
* JDBC Basics
(http://java.sun.com/docs/books/tutorial/jdbc/basics/index.htm
l) --- A tutorial from Sun covering beginner topics in JDBC
* JDBC Short Course
(http://java.sun.com/developer/onlineTraining/Database/JDBCSho
rtCourse/index.html) --- A more in-depth tutorial from Sun and
JGuru
Key topics:
* For help with connection strings, connection options setting
up your connection through JDBC, see Section 4.1,
"Driver/Datasource Class Names, URL Syntax and Configuration
Properties for Connector/J."
* For tips on using Connector/J and JDBC with generic J2EE
toolkits, see Section 5.2, "Using Connector/J with J2EE and
Other Java Frameworks."
* Developers using the Tomcat server platform, see Section
5.2.2, "Using Connector/J with Tomcat."
* Developers using JBoss, see Section 5.2.3, "Using Connector/J
with JBoss."
* Developers using Spring, see Section 5.2.4, "Using Connector/J
with Spring."
MySQL Enterprise MySQL Enterprise subscribers will find more
information about using JDBC with MySQL in the Knowledge Base
articles about JDBC
(https://kb.mysql.com/search.php?cat=search&category=10). Access
to the MySQL Knowledge Base collection of articles is one of the
advantages of subscribing to MySQL Enterprise. For more
information see
http://www.mysql.com/products/enterprise/advisors.html.
Chapter 1. Connector/J Versions
There are currently four versions of MySQL Connector/J available:
* Connector/J 5.1 is the Type IV pure Java JDBC driver and
provides compatibility with all the functionality of MySQL,
including 4.1, 5.0, 5.1 and the 6.0 alpha release featuring
the new Falcon storage engine. Connector/J 5.1 provides ease
of development features, including auto-registration with the
Driver Manager, standardized validity checks, categorized
SQLExceptions, support for the JDBC-4.0 XML processing, per
connection client information, NCHAR, NVARCHAR and NCLOB
types. This release also includes all bug fixes up to and
including Connector/J 5.0.6.
* Connector/J 5.0 provides support for all the functionality
offered by Connector/J 3.1 and includes distributed
transaction (XA) support.
* Connector/J 3.1 was designed for connectivity to MySQL 4.1 and
MySQL 5.0 servers and provides support for all the
functionality in MySQL 5.0 except distributed transaction (XA)
support.
* Connector/J 3.0 provides core functionality and was designed
with connectivity to MySQL 3.x or MySQL 4.1 servers, although
it will provide basic compatibility with later versions of
MySQL. Connector/J 3.0 does not support server-side prepared
statements, and does not support any of the features in
versions of MySQL later than 4.1.
The current recommended version for Connector/J is 5.1. This guide
covers all three connector versions, with specific notes given
where a setting applies to a specific option.
1.1. Java Versions Supported
MySQL Connector/J supports Java-2 JVMs, including:
* JDK 1.2.x (only for Connector/J 3.1.x or earlier)
* JDK 1.3.x
* JDK 1.4.x
* JDK 1.5.x
* JDK 1.6.x
If you are building Connector/J from source using the source
distribution (see Section 2.4, "Installing from the Development
Source Tree") then you must use JDK 1.4.x or newer to compiler the
Connector package. For Connector/J 5.1 you must use JDK-1.6.x.
MySQL Connector/J does not support JDK-1.1.x or JDK-1.0.x.
Because of the implementation of java.sql.Savepoint, Connector/J
3.1.0 and newer will not run on JDKs older than 1.4 unless the
class verifier is turned off (by setting the -Xverify:none option
to the Java runtime). This is because the class verifier will try
to load the class definition for java.sql.Savepoint even though it
is not accessed by the driver unless you actually use savepoint
functionality.
Caching functionality provided by Connector/J 3.1.0 or newer is
also not available on JVMs older than 1.4.x, as it relies on
java.util.LinkedHashMap which was first available in JDK-1.4.0.
Chapter 2. Connector/J Installation
You can install the Connector/J package using two methods, using
either the binary or source distribution. The binary distribution
provides the easiest methods for installation; the source
distribution enables you to customize your installation further.
With either solution, you must manually add the Connector/J
location to your Java CLASSPATH.
If you are upgrading from a previous version, read the upgrade
information before continuing. See Section 2.3, "Upgrading from an
Older Version."
2.1. Installing Connector/J from a Binary Distribution
The easiest method of installation is to use the binary
distribution of the Connector/J package. The binary distribution
is available either as a Tar/Gzip or Zip file which you must
extract to a suitable location and then optionally make the
information about the package available by changing your CLASSPATH
(see Section 2.2, "Installing the Driver and Configuring the
CLASSPATH").
MySQL Connector/J is distributed as a .zip or .tar.gz archive
containing the sources, the class files, and the JAR archive named
mysql-connector-java-[version]-bin.jar, and starting with
Connector/J 3.1.8 a debug build of the driver in a file named
mysql-connector-java-[version]-bin-g.jar.
Starting with Connector/J 3.1.9, the .class files that constitute
the JAR files are only included as part of the driver JAR file.
You should not use the debug build of the driver unless instructed
to do so when reporting a problem or a bug to MySQL AB, as it is
not designed to be run in production environments, and will have
adverse performance impact when used. The debug binary also
depends on the Aspect/J runtime library, which is located in the
src/lib/aspectjrt.jar file that comes with the Connector/J
distribution.
You will need to use the appropriate graphical or command-line
utility to extract the distribution (for example, WinZip for the
.zip archive, and tar for the .tar.gz archive). Because there are
potentially long filenames in the distribution, we use the GNU tar
archive format. You will need to use GNU tar (or an application
that understands the GNU tar archive format) to unpack the .tar.gz
variant of the distribution.
2.2. Installing the Driver and Configuring the CLASSPATH
Once you have extracted the distribution archive, you can install
the driver by placing mysql-connector-java-[version]-bin.jar in
your classpath, either by adding the full path to it to your
CLASSPATH environment variable, or by directly specifying it with
the command line switch -cp when starting your JVM.
If you are going to use the driver with the JDBC DriverManager,
you would use com.mysql.jdbc.Driver as the class that implements
java.sql.Driver.
You can set the CLASSPATH environment variable under UNIX, Linux
or Mac OS X either locally for a user within their .profile,
.login or other login file. You can also set it globally by
editing the global /etc/profile file.
For example, under a C shell (csh, tcsh) you would add the
Connector/J driver to your CLASSPATH using the following:
shell> setenv CLASSPATH /path/mysql-connector-java-[ver]-bin.jar:$CLA
SSPATH
Or with a Bourne-compatible shell (sh, ksh, bash):
export set CLASSPATH=/path/mysql-connector-java-[ver]-bin.jar:$CLASSP
ATH
Within Windows 2000, Windows XP and Windows Server 2003, you must
set the environment variable through the System control panel.
If you want to use MySQL Connector/J with an application server
such as Tomcat or JBoss, you will have to read your vendor's
documentation for more information on how to configure third-party
class libraries, as most application servers ignore the CLASSPATH
environment variable. For configuration examples for some J2EE
application servers, see Section 5.2, "Using Connector/J with J2EE
and Other Java Frameworks." However, the authoritative source for
JDBC connection pool configuration information for your particular
application server is the documentation for that application
server.
If you are developing servlets or JSPs, and your application
server is J2EE-compliant, you can put the driver's .jar file in
the WEB-INF/lib subdirectory of your webapp, as this is a standard
location for third party class libraries in J2EE web applications.
You can also use the MysqlDataSource or
MysqlConnectionPoolDataSource classes in the
com.mysql.jdbc.jdbc2.optional package, if your J2EE application
server supports or requires them. Starting with Connector/J 5.0.0,
the javax.sql.XADataSource interface is implemented via the
com.mysql.jdbc.jdbc2.optional.MysqlXADataSource class, which
supports XA distributed transactions when used in combination with
MySQL server version 5.0.
The various MysqlDataSource classes support the following
parameters (through standard set mutators):
* user
* password
* serverName (see the previous section about fail-over hosts)
* databaseName
* port
2.3. Upgrading from an Older Version
MySQL AB tries to keep the upgrade process as easy as possible,
however as is the case with any software, sometimes changes need
to be made in new versions to support new features, improve
existing functionality, or comply with new standards.
This section has information about what users who are upgrading
from one version of Connector/J to another (or to a new version of
the MySQL server, with respect to JDBC functionality) should be
aware of.
2.3.1. Upgrading from MySQL Connector/J 3.0 to 3.1
Connector/J 3.1 is designed to be backward-compatible with
Connector/J 3.0 as much as possible. Major changes are isolated to
new functionality exposed in MySQL-4.1 and newer, which includes
Unicode character sets, server-side prepared statements, SQLState
codes returned in error messages by the server and various
performance enhancements that can be enabled or disabled via
configuration properties.
* Unicode Character Sets --- See the next section, as well as
Character Set Support
(http://dev.mysql.com/doc/refman/4.1/en/charset.html), for
information on this new feature of MySQL. If you have
something misconfigured, it will usually show up as an error
with a message similar to Illegal mix of collations.
* Server-side Prepared Statements --- Connector/J 3.1 will
automatically detect and use server-side prepared statements
when they are available (MySQL server version 4.1.0 and
newer).
Starting with version 3.1.7, the driver scans SQL you are
preparing via all variants of Connection.prepareStatement() to
determine if it is a supported type of statement to prepare on
the server side, and if it is not supported by the server, it
instead prepares it as a client-side emulated prepared
statement. You can disable this feature by passing
emulateUnsupportedPstmts=false in your JDBC URL.
If your application encounters issues with server-side
prepared statements, you can revert to the older client-side
emulated prepared statement code that is still presently used
for MySQL servers older than 4.1.0 with the connection
property useServerPrepStmts=false
* Datetimes with all-zero components (0000-00-00 ...) --- These
values can not be represented reliably in Java. Connector/J
3.0.x always converted them to NULL when being read from a
ResultSet.
Connector/J 3.1 throws an exception by default when these
values are encountered as this is the most correct behavior
according to the JDBC and SQL standards. This behavior can be
modified using the zeroDateTimeBehavior configuration
property. The allowable values are:
+ exception (the default), which throws an SQLException
with an SQLState of S1009.
+ convertToNull, which returns NULL instead of the date.
+ round, which rounds the date to the nearest closest value
which is 0001-01-01.
Starting with Connector/J 3.1.7, ResultSet.getString() can be
decoupled from this behavior via noDatetimeStringSync=true
(the default value is false) so that you can get retrieve the
unaltered all-zero value as a String. It should be noted that
this also precludes using any time zone conversions, therefore
the driver will not allow you to enable noDatetimeStringSync
and useTimezone at the same time.
* New SQLState Codes --- Connector/J 3.1 uses SQL:1999 SQLState
codes returned by the MySQL server (if supported), which are
different from the legacy X/Open state codes that Connector/J
3.0 uses. If connected to a MySQL server older than
MySQL-4.1.0 (the oldest version to return SQLStates as part of
the error code), the driver will use a built-in mapping. You
can revert to the old mapping by using the configuration
property useSqlStateCodes=false.
* ResultSet.getString() --- Calling ResultSet.getString() on a
BLOB column will now return the address of the byte[] array
that represents it, instead of a String representation of the
BLOB. BLOBs have no character set, so they can't be converted
to java.lang.Strings without data loss or corruption.
To store strings in MySQL with LOB behavior, use one of the
TEXT types, which the driver will treat as a java.sql.Clob.
* Debug builds --- Starting with Connector/J 3.1.8 a debug build
of the driver in a file named
mysql-connector-java-[version]-bin-g.jar is shipped alongside
the normal binary jar file that is named
mysql-connector-java-[version]-bin.jar.
Starting with Connector/J 3.1.9, we don't ship the .class
files unbundled, they are only available in the JAR archives
that ship with the driver.
You should not use the debug build of the driver unless
instructed to do so when reporting a problem or bug to MySQL
AB, as it is not designed to be run in production
environments, and will have adverse performance impact when
used. The debug binary also depends on the Aspect/J runtime
library, which is located in the src/lib/aspectjrt.jar file
that comes with the Connector/J distribution.
2.3.2. Upgrading to MySQL Connector/J 5.1.x
* In Connector/J 5.0.x and earlier, the alias for a table in a
SELECT statement is returned when accessing the result set
metadata using ResultSetMetaData.getColumnName(). This
behavior however is not JDBC compliant, and in Connector/J 5.1
this behavior was changed so that the original table name,
rather than the alias, is returned.
The JDBC-compliant behavior is designed to let API users
reconstruct the DML statement based on the metadata within
ResultSet and ResultSetMetaData.
You can get the alias for a column in a result set by calling
ResultSetMetaData.getColumnLabel(). If you want to use the old
non-compliant behavior with ResultSetMetaData.getColumnName(),
use the useOldAliasMetadataBehavior option and set the value
to true.
In Connector/J 5.0.x the default value of
useOldAliasMetadataBehavior was true, but in Connector/J 5.1
this was changed to a default value of false.
2.3.3. JDBC-Specific Issues When Upgrading to MySQL Server 4.1 or
Newer
* Using the UTF-8 Character Encoding - Prior to MySQL server
version 4.1, the UTF-8 character encoding was not supported by
the server, however the JDBC driver could use it, allowing
storage of multiple character sets in latin1 tables on the
server.
Starting with MySQL-4.1, this functionality is deprecated. If
you have applications that rely on this functionality, and can
not upgrade them to use the official Unicode character support
in MySQL server version 4.1 or newer, you should add the
following property to your connection URL:
useOldUTF8Behavior=true
* Server-side Prepared Statements - Connector/J 3.1 will
automatically detect and use server-side prepared statements
when they are available (MySQL server version 4.1.0 and
newer). If your application encounters issues with server-side
prepared statements, you can revert to the older client-side
emulated prepared statement code that is still presently used
for MySQL servers older than 4.1.0 with the following
connection property:
useServerPrepStmts=false
2.4. Installing from the Development Source Tree
Caution
You should read this section only if you are interested in helping
us test our new code. If you just want to get MySQL Connector/J up
and running on your system, you should use a standard release
distribution.
To install MySQL Connector/J from the development source tree,
make sure that you have the following prerequisites:
* Subversion, to check out the sources from our repository
(available from http://subversion.tigris.org/).
* Apache Ant version 1.6 or newer (available from
http://ant.apache.org/).
* JDK-1.4.2 or later. Although MySQL Connector/J can be
installed on older JDKs, to compile it from source you must
have at least JDK-1.4.2.
The Subversion source code repository for MySQL Connector/J is
located at http://svn.mysql.com/svnpublic/connector-j. In general,
you should not check out the entire repository because it contains
every branch and tag for MySQL Connector/J and is quite large.
To check out and compile a specific branch of MySQL Connector/J,
follow these steps:
1. Check out the latest code from the branch that you want with
the following command (replacing [major] and [minor] with
appropriate version numbers):
shell> svn co »
http://svn.mysql.com/svnpublic/connector-j/branches/branch_[major]_[m
inor]/connector-j
This creates a connector-j subdirectory in the current
directory that contains the latest sources for the requested
branch.
2. Change location to the connector-j directory to make it your
current working directory:
shell> cd connector-j
3. Issue the following command to compile the driver and create a
.jar file suitable for installation:
shell> ant dist
This creates a build directory in the current directory, where
all build output will go. A directory is created in the build
directory that includes the version number of the sources you
are building from. This directory contains the sources,
compiled .class files, and a .jar file suitable for
deployment. For other possible targets, including ones that
will create a fully packaged distribution, issue the following
command:
shell> ant -projecthelp
4. A newly created .jar file containing the JDBC driver will be
placed in the directory build/mysql-connector-java-[version].
Install the newly created JDBC driver as you would a binary
.jar file that you download from MySQL by following the
instructions in Section 2.2, "Installing the Driver and
Configuring the CLASSPATH."
If you want to build the Connector/J 5.1 branch then you must have
a compatible JDK 6.0 installed.
Chapter 3. Connector/J Examples
Examples of using Connector/J are located throughout this
document, this section provides a summary and links to these
examples.
* Example 5.1.1, "Obtaining a connection from the DriverManager"
* Example 5.1.2, "Using java.sql.Statement to execute a SELECT
query"
* Example 5.1.3, "Stored Procedures"
* Example 5.1.3, "Using Connection.prepareCall()"
* Example 5.1.3, "Registering output parameters"
* Example 5.1.3, "Setting CallableStatement input parameters"
* Example 5.1.3, "Retrieving results and output parameter
values"
* Example 5.1.4, "Retrieving AUTO_INCREMENT column values using
Statement.getGeneratedKeys()"
* Example 5.1.4, "Retrieving AUTO_INCREMENT column values using
SELECT LAST_INSERT_ID()"
* Example 5.1.4, "Retrieving AUTO_INCREMENT column values in
Updatable ResultSets"
* Example 5.2.1.1, "Using a connection pool with a J2EE
application server"
* Example 5.3, "Example of transaction with retry logic"
Chapter 4. Connector/J (JDBC) Reference
This section of the manual contains reference material for MySQL
Connector/J, some of which is automatically generated during the
Connector/J build process.
4.1. Driver/Datasource Class Names, URL Syntax and Configuration
Properties for Connector/J
The name of the class that implements java.sql.Driver in MySQL
Connector/J is com.mysql.jdbc.Driver. The org.gjt.mm.mysql.Driver
class name is also usable to remain backward-compatible with
MM.MySQL. You should use this class name when registering the
driver, or when otherwise configuring software to use MySQL
Connector/J.
The JDBC URL format for MySQL Connector/J is as follows, with
items in square brackets ([, ]) being optional:
jdbc:mysql://[host][,failoverhost...][:port]/[database] »
[?propertyName1][=propertyValue1][&propertyName2][=propertyValue2]...
If the hostname is not specified, it defaults to 127.0.0.1. If the
port is not specified, it defaults to 3306, the default port
number for MySQL servers.
jdbc:mysql://[host:port],[host:port].../[database] »
[?propertyName1][=propertyValue1][&propertyName2][=propertyValue2]...
If the database is not specified, the connection will be made with
no default database. In this case, you will need to either call
the setCatalog() method on the Connection instance or
fully-specify table names using the database name (i.e. SELECT
dbname.tablename.colname FROM dbname.tablename...) in your SQL.
Not specifying the database to use upon connection is generally
only useful when building tools that work with multiple databases,
such as GUI database managers.
MySQL Connector/J has fail-over support. This allows the driver to
fail-over to any number of slave hosts and still perform read-only
queries. Fail-over only happens when the connection is in an
autoCommit(true) state, because fail-over can not happen reliably
when a transaction is in progress. Most application servers and
connection pools set autoCommit to true at the end of every
transaction/connection use.
The fail-over functionality has the following behavior:
* If the URL property autoReconnect is false: Failover only
happens at connection initialization, and failback occurs when
the driver determines that the first host has become available
again.
* If the URL property autoReconnect is true: Failover happens
when the driver determines that the connection has failed
(before every query), and falls back to the first host when it
determines that the host has become available again (after
queriesBeforeRetryMaster queries have been issued).
In either case, whenever you are connected to a "failed-over"
server, the connection will be set to read-only state, so queries
that would modify data will have exceptions thrown (the query will
never be processed by the MySQL server).
Configuration properties define how Connector/J will make a
connection to a MySQL server. Unless otherwise noted, properties
can be set for a DataSource object or for a Connection object.
Configuration Properties can be set in one of the following ways:
* Using the set*() methods on MySQL implementations of
java.sql.DataSource (which is the preferred method when using
implementations of java.sql.DataSource):
+ com.mysql.jdbc.jdbc2.optional.MysqlDataSource
+ com.mysql.jdbc.jdbc2.optional.MysqlConnectionPoolDataSour
ce
* As a key/value pair in the java.util.Properties instance
passed to DriverManager.getConnection() or Driver.connect()
* As a JDBC URL parameter in the URL given to
java.sql.DriverManager.getConnection(),
java.sql.Driver.connect() or the MySQL implementations of the
javax.sql.DataSource setURL() method.
Note
If the mechanism you use to configure a JDBC URL is XML-based,
you will need to use the XML character literal & to
separate configuration parameters, as the ampersand is a
reserved character for XML.
The properties are listed in the following tables.
Connection/Authentication.
Property Name Definition Default Value Since Version
user The user to connect as all versions
password The password to use when connecting all versions
socketFactory The name of the class that the driver should use for
creating socket connections to the server. This class must
implement the interface 'com.mysql.jdbc.SocketFactory' and have
public no-args constructor. com.mysql.jdbc.StandardSocketFactory
3.0.3
connectTimeout Timeout for socket connect (in milliseconds), with
0 being no timeout. Only works on JDK-1.4 or newer. Defaults to
'0'. 0 3.0.1
socketTimeout Timeout on network socket operations (0, the default
means no timeout). 0 3.0.1
connectionLifecycleInterceptors A comma-delimited list of classes
that implement "com.mysql.jdbc.ConnectionLifecycleInterceptor"
that should notified of connection lifecycle events (creation,
destruction, commit, rollback, setCatalog and setAutoCommit) and
potentially alter the execution of these commands.
ConnectionLifecycleInterceptors are "stackable", more than one
interceptor may be specified via the configuration property as a
comma-delimited list, with the interceptors executed in order from
left to right. 5.1.4
useConfigs Load the comma-delimited list of configuration
properties before parsing the URL or applying user-specified
properties. These configurations are explained in the
'Configurations' of the documentation. 3.1.5
interactiveClient Set the CLIENT_INTERACTIVE flag, which tells
MySQL to timeout connections based on INTERACTIVE_TIMEOUT instead
of WAIT_TIMEOUT false 3.1.0
localSocketAddress Hostname or IP address given to explicitly
configure the interface that the driver will bind the client side
of the TCP/IP connection to when connecting. 5.0.5
propertiesTransform An implementation of
com.mysql.jdbc.ConnectionPropertiesTransform that the driver will
use to modify URL properties passed to the driver before
attempting a connection 3.1.4
useCompression Use zlib compression when communicating with the
server (true/false)? Defaults to 'false'. false 3.0.17
Networking.
Property Name Definition Default Value Since Version
tcpKeepAlive If connecting using TCP/IP, should the driver set
SO_KEEPALIVE? true 5.0.7
tcpNoDelay If connecting using TCP/IP, should the driver set
SO_TCP_NODELAY (disabling the Nagle Algorithm)? true 5.0.7
tcpRcvBuf If connecting using TCP/IP, should the driver set
SO_RCV_BUF to the given value? The default value of '0', means use
the platform default value for this property) 0 5.0.7
tcpSndBuf If connecting using TCP/IP, shuold the driver set
SO_SND_BUF to the given value? The default value of '0', means use
the platform default value for this property) 0 5.0.7
tcpTrafficClass If connecting using TCP/IP, should the driver set
traffic class or type-of-service fields ?See the documentation for
java.net.Socket.setTrafficClass() for more information. 0 5.0.7
High Availability and Clustering.
Property Name Definition Default Value Since Version
autoReconnect Should the driver try to re-establish stale and/or
dead connections? If enabled the driver will throw an exception
for a queries issued on a stale or dead connection, which belong
to the current transaction, but will attempt reconnect before the
next query issued on the connection in a new transaction. The use
of this feature is not recommended, because it has side effects
related to session state and data consistency when applications
don't handle SQLExceptions properly, and is only designed to be
used when you are unable to configure your application to handle
SQLExceptions resulting from dead and stale connections properly.
Alternatively, investigate setting the MySQL server variable
"wait_timeout" to some high value rather than the default of 8
hours. false 1.1
autoReconnectForPools Use a reconnection strategy appropriate for
connection pools (defaults to 'false') false 3.1.3
failOverReadOnly When failing over in autoReconnect mode, should
the connection be set to 'read-only'? true 3.0.12
maxReconnects Maximum number of reconnects to attempt if
autoReconnect is true, default is '3'. 3 1.1
reconnectAtTxEnd If autoReconnect is set to true, should the
driver attempt reconnections at the end of every transaction?
false 3.0.10
initialTimeout If autoReconnect is enabled, the initial time to
wait between re-connect attempts (in seconds, defaults to '2'). 2
1.1
roundRobinLoadBalance When autoReconnect is enabled, and
failoverReadonly is false, should we pick hosts to connect to on a
round-robin basis? false 3.1.2
queriesBeforeRetryMaster Number of queries to issue before falling
back to master when failed over (when using multi-host failover).
Whichever condition is met first, 'queriesBeforeRetryMaster' or
'secondsBeforeRetryMaster' will cause an attempt to be made to
reconnect to the master. Defaults to 50. 50 3.0.2
secondsBeforeRetryMaster How long should the driver wait, when
failed over, before attempting 30 3.0.2
resourceId A globally unique name that identifies the resource
that this datasource or connection is connected to, used for
XAResource.isSameRM() when the driver can't determine this value
based on hostnames used in the URL 5.0.1
Security.
Property Name Definition Default Value Since Version
allowMultiQueries Allow the use of ';' to delimit multiple queries
during one statement (true/false), defaults to 'false' false 3.1.1
useSSL Use SSL when communicating with the server (true/false),
defaults to 'false' false 3.0.2
requireSSL Require SSL connection if useSSL=true? (defaults to
'false'). false 3.1.0
allowLoadLocalInfile Should the driver allow use of 'LOAD DATA
LOCAL INFILE...' (defaults to 'true'). true 3.0.3
allowUrlInLocalInfile Should the driver allow URLs in 'LOAD DATA
LOCAL INFILE' statements? false 3.1.4
clientCertificateKeyStorePassword Password for the client
certificates KeyStore 5.1.0
clientCertificateKeyStoreType KeyStore type for client
certificates (NULL or empty means use default, standard keystore
types supported by the JVM are "JKS" and "PKCS12", your
environment may have more available depending on what security
products are installed and available to the JVM. 5.1.0
clientCertificateKeyStoreUrl URL to the client certificate
KeyStore (if not specified, use defaults) 5.1.0
trustCertificateKeyStorePassword Password for the trusted root
certificates KeyStore 5.1.0
trustCertificateKeyStoreType KeyStore type for trusted root
certificates (NULL or empty means use default, standard keystore
types supported by the JVM are "JKS" and "PKCS12", your
environment may have more available depending on what security
products are installed and available to the JVM. 5.1.0
trustCertificateKeyStoreUrl URL to the trusted root certificate
KeyStore (if not specified, use defaults) 5.1.0
paranoid Take measures to prevent exposure sensitive information
in error messages and clear data structures holding sensitive data
when possible? (defaults to 'false') false 3.0.1
Performance Extensions.
Property Name Definition Default Value Since Version
callableStmtCacheSize If 'cacheCallableStmts' is enabled, how many
callable statements should be cached? 100 3.1.2
metadataCacheSize The number of queries to cache ResultSetMetadata
for if cacheResultSetMetaData is set to 'true' (default 50) 50
3.1.1
prepStmtCacheSize If prepared statement caching is enabled, how
many prepared statements should be cached? 25 3.0.10
prepStmtCacheSqlLimit If prepared statement caching is enabled,
what's the largest SQL the driver will cache the parsing for? 256
3.0.10
alwaysSendSetIsolation Should the driver always communicate with
the database when Connection.setTransactionIsolation() is called?
If set to false, the driver will only communicate with the
database when the requested transaction isolation is different
than the whichever is newer, the last value that was set via
Connection.setTransactionIsolation(), or the value that was read
from the server when the connection was established. true 3.1.7
maintainTimeStats Should the driver maintain various internal
timers to enable idle time calculations as well as more verbose
error messages when the connection to the server fails? Setting
this property to false removes at least two calls to
System.getCurrentTimeMillis() per query. true 3.1.9
useCursorFetch If connected to MySQL > 5.0.2, and setFetchSize() >
0 on a statement, should that statement use cursor-based fetching
to retrieve rows? false 5.0.0
blobSendChunkSize Chunk to use when sending BLOB/CLOBs via
ServerPreparedStatements 1048576 3.1.9
cacheCallableStmts Should the driver cache the parsing stage of
CallableStatements false 3.1.2
cachePrepStmts Should the driver cache the parsing stage of
PreparedStatements of client-side prepared statements, the "check"
for suitability of server-side prepared and server-side prepared
statements themselves? false 3.0.10
cacheResultSetMetadata Should the driver cache ResultSetMetaData
for Statements and PreparedStatements? (Req. JDK-1.4+, true/false,
default 'false') false 3.1.1
cacheServerConfiguration Should the driver cache the results of
'SHOW VARIABLES' and 'SHOW COLLATION' on a per-URL basis? false
3.1.5
defaultFetchSize The driver will call setFetchSize(n) with this
value on all newly-created Statements 0 3.1.9
dontTrackOpenResources The JDBC specification requires the driver
to automatically track and close resources, however if your
application doesn't do a good job of explicitly calling close() on
statements or result sets, this can cause memory leakage. Setting
this property to true relaxes this constraint, and can be more
memory efficient for some applications. false 3.1.7
dynamicCalendars Should the driver retrieve the default calendar
when required, or cache it per connection/session? false 3.1.5
elideSetAutoCommits If using MySQL-4.1 or newer, should the driver
only issue 'set autocommit=n' queries when the server's state
doesn't match the requested state by
Connection.setAutoCommit(boolean)? false 3.1.3
enableQueryTimeouts When enabled, query timeouts set via
Statement.setQueryTimeout() use a shared java.util.Timer instance
for scheduling. Even if the timeout doesn't expire before the
query is processed, there will be memory used by the TimerTask for
the given timeout which won't be reclaimed until the time the
timeout would have expired if it hadn't been cancelled by the
driver. High-load environments might want to consider disabling
this functionality. true 5.0.6
holdResultsOpenOverStatementClose Should the driver close result
sets on Statement.close() as required by the JDBC specification?
false 3.1.7
largeRowSizeThreshold What size result set row should the JDBC
driver consider "large", and thus use a more memory-efficient way
of representing the row internally? 2048 5.1.1
loadBalanceStrategy If using a load-balanced connection to connect
to SQL nodes in a MySQL Cluster/NDB configuration (by using the
URL prefix "jdbc:mysql:loadbalance://"), which load balancing
algorithm should the driver use: (1) "random" - the driver will
pick a random host for each request. This tends to work better
than round-robin, as the randomness will somewhat account for
spreading loads where requests vary in response time, while
round-robin can sometimes lead to overloaded nodes if there are
variations in response times across the workload. (2)
"bestResponseTime" - the driver will route the request to the host
that had the best response time for the previous transaction.
random 5.0.6
locatorFetchBufferSize If 'emulateLocators' is configured to
'true', what size buffer should be used when fetching BLOB data
for getBinaryInputStream? 1048576 3.2.1
rewriteBatchedStatements Should the driver use multiqueries
(irregardless of the setting of "allowMultiQueries") as well as
rewriting of prepared statements for INSERT into multi-value
inserts when executeBatch() is called? Notice that this has the
potential for SQL injection if using plain java.sql.Statements and
your code doesn't sanitize input correctly. Notice that for
prepared statements, server-side prepared statements can not
currently take advantage of this rewrite option, and that if you
don't specify stream lengths when using
PreparedStatement.set*Stream(), the driver won't be able to
determine the optimum number of parameters per batch and you might
receive an error from the driver that the resultant packet is too
large. Statement.getGeneratedKeys() for these rewritten statements
only works when the entire batch includes INSERT statements. false
3.1.13
useDirectRowUnpack Use newer result set row unpacking code that
skips a copy from network buffers to a MySQL packet instance and
instead reads directly into the result set row data buffers. true
5.1.1
useDynamicCharsetInfo Should the driver use a per-connection cache
of character set information queried from the server when
necessary, or use a built-in static mapping that is more
efficient, but isn't aware of custom character sets or character
sets implemented after the release of the JDBC driver? true 5.0.6
useFastDateParsing Use internal String->Date/Time/Timestamp
conversion routines to avoid excessive object creation? true 5.0.5
useFastIntParsing Use internal String->Integer conversion routines
to avoid excessive object creation? true 3.1.4
useJvmCharsetConverters Always use the character encoding routines
built into the JVM, rather than using lookup tables for
single-byte character sets? false 5.0.1
useLocalSessionState Should the driver refer to the internal
values of autocommit and transaction isolation that are set by
Connection.setAutoCommit() and
Connection.setTransactionIsolation() and transaction state as
maintained by the protocol, rather than querying the database or
blindly sending commands to the database for commit() or
rollback() method calls? false 3.1.7
useReadAheadInput Use newer, optimized non-blocking, buffered
input stream when reading from the server? true 3.1.5
Debugging/Profiling.
Property Name Definition Default Value Since Version
logger The name of a class that implements
"com.mysql.jdbc.log.Log" that will be used to log messages to.
(default is "com.mysql.jdbc.log.StandardLogger", which logs to
STDERR) com.mysql.jdbc.log.StandardLogger 3.1.1
gatherPerfMetrics Should the driver gather performance metrics,
and report them via the configured logger every
'reportMetricsIntervalMillis' milliseconds? false 3.1.2
profileSQL Trace queries and their execution/fetch times to the
configured logger (true/false) defaults to 'false' false 3.1.0
profileSql Deprecated, use 'profileSQL' instead. Trace queries and
their execution/fetch times on STDERR (true/false) defaults to
'false' 2.0.14
reportMetricsIntervalMillis If 'gatherPerfMetrics' is enabled, how
often should they be logged (in ms)? 30000 3.1.2
maxQuerySizeToLog Controls the maximum length/size of a query that
will get logged when profiling or tracing 2048 3.1.3
packetDebugBufferSize The maximum number of packets to retain when
'enablePacketDebug' is true 20 3.1.3
slowQueryThresholdMillis If 'logSlowQueries' is enabled, how long
should a query (in ms) before it is logged as 'slow'? 2000 3.1.2
slowQueryThresholdNanos If 'useNanosForElapsedTime' is set to
true, and this property is set to a non-zero value, the driver
will use this threshold (in nanosecond units) to determine if a
query was slow. 0 5.0.7
useUsageAdvisor Should the driver issue 'usage' warnings advising
proper and efficient usage of JDBC and MySQL Connector/J to the
log (true/false, defaults to 'false')? false 3.1.1
autoGenerateTestcaseScript Should the driver dump the SQL it is
executing, including server-side prepared statements to STDERR?
false 3.1.9
autoSlowLog Instead of using slowQueryThreshold* to determine if a
query is slow enough to be logged, maintain statistics that allow
the driver to determine queries that are outside the 99th
percentile? true 5.1.4
clientInfoProvider The name of a class that implements the
com.mysql.jdbc.JDBC4ClientInfoProvider interface in order to
support JDBC-4.0's Connection.get/setClientInfo() methods
com.mysql.jdbc.JDBC4CommentClientInfoProvider 5.1.0
dumpMetadataOnColumnNotFound Should the driver dump the
field-level metadata of a result set into the exception message
when ResultSet.findColumn() fails? false 3.1.13
dumpQueriesOnException Should the driver dump the contents of the
query sent to the server in the message for SQLExceptions? false
3.1.3
enablePacketDebug When enabled, a ring-buffer of
'packetDebugBufferSize' packets will be kept, and dumped when
exceptions are thrown in key areas in the driver's code false
3.1.3
explainSlowQueries If 'logSlowQueries' is enabled, should the
driver automatically issue an 'EXPLAIN' on the server and send the
results to the configured log at a WARN level? false 3.1.2
includeInnodbStatusInDeadlockExceptions Include the output of
"SHOW ENGINE INNODB STATUS" in exception messages when deadlock
exceptions are detected? false 5.0.7
logSlowQueries Should queries that take longer than
'slowQueryThresholdMillis' be logged? false 3.1.2
logXaCommands Should the driver log XA commands sent by
MysqlXaConnection to the server, at the DEBUG level of logging?
false 5.0.5
resultSetSizeThreshold If the usage advisor is enabled, how many
rows should a result set contain before the driver warns that it
is suspiciously large? 100 5.0.5
traceProtocol Should trace-level network protocol be logged? false
3.1.2
useNanosForElapsedTime For profiling/debugging functionality that
measures elapsed time, should the driver try to use nanoseconds
resolution if available (JDK >= 1.5)? false 5.0.7
Miscellaneous.
Property Name Definition Default Value Since Version
useUnicode Should the driver use Unicode character encodings when
handling strings? Should only be used when the driver can't
determine the character set mapping, or you are trying to 'force'
the driver to use a character set that MySQL either doesn't
natively support (such as UTF-8), true/false, defaults to 'true'
true 1.1g
characterEncoding If 'useUnicode' is set to true, what character
encoding should the driver use when dealing with strings?
(defaults is to 'autodetect') 1.1g
characterSetResults Character set to tell the server to return
results as. 3.0.13
connectionCollation If set, tells the server to use this collation
via 'set collation_connection' 3.0.13
useBlobToStoreUTF8OutsideBMP Tells the driver to treat
[MEDIUM/LONG]BLOB columns as [LONG]VARCHAR columns holding text
encoded in UTF-8 that has characters outside the BMP (4-byte
encodings), which MySQL server can't handle natively. false 5.1.3
utf8OutsideBmpExcludedColumnNamePattern When
"useBlobToStoreUTF8OutsideBMP" is set to "true", column names
matching the given regex will still be treated as BLOBs unless
they match the regex specified for
"utf8OutsideBmpIncludedColumnNamePattern". The regex must follow
the patterns used for the java.util.regex package. 5.1.3
utf8OutsideBmpIncludedColumnNamePattern Used to specify exclusion
rules to "utf8OutsideBmpExcludedColumnNamePattern". The regex must
follow the patterns used for the java.util.regex package. 5.1.3
sessionVariables A comma-separated list of name/value pairs to be
sent as SET SESSION ... to the server when the driver connects.
3.1.8
allowNanAndInf Should the driver allow NaN or +/- INF values in
PreparedStatement.setDouble()? false 3.1.5
autoClosePStmtStreams Should the driver automatically call
.close() on streams/readers passed as arguments via set*()
methods? false 3.1.12
autoDeserialize Should the driver automatically detect and
de-serialize objects stored in BLOB fields? false 3.1.5
blobsAreStrings Should the driver always treat BLOBs as Strings -
specifically to work around dubious metadata returned by the
server for GROUP BY clauses? false 5.0.8
capitalizeTypeNames Capitalize type names in DatabaseMetaData?
(usually only useful when using WebObjects, true/false, defaults
to 'false') true 2.0.7
clobCharacterEncoding The character encoding to use for sending
and retrieving TEXT, MEDIUMTEXT and LONGTEXT values instead of the
configured connection characterEncoding 5.0.0
clobberStreamingResults This will cause a 'streaming' ResultSet to
be automatically closed, and any outstanding data still streaming
from the server to be discarded if another query is executed
before all the data has been read from the server. false 3.0.9
continueBatchOnError Should the driver continue processing batch
commands if one statement fails. The JDBC spec allows either way
(defaults to 'true'). true 3.0.3
createDatabaseIfNotExist Creates the database given in the URL if
it doesn't yet exist. Assumes the configured user has permissions
to create databases. false 3.1.9
emptyStringsConvertToZero Should the driver allow conversions from
empty string fields to numeric values of '0'? true 3.1.8
emulateLocators Should the driver emulate java.sql.Blobs with
locators? With this feature enabled, the driver will delay loading
the actual Blob data until the one of the retrieval methods
(getInputStream(), getBytes(), and so forth) on the blob data
stream has been accessed. For this to work, you must use a column
alias with the value of the column to the actual name of the Blob.
The feature also has the following restrictions: The SELECT that
created the result set must reference only one table, the table
must have a primary key; the SELECT must alias the original blob
column name, specified as a string, to an alternate name; the
SELECT must cover all columns that make up the primary key. false
3.1.0
emulateUnsupportedPstmts Should the driver detect prepared
statements that are not supported by the server, and replace them
with client-side emulated versions? true 3.1.7
functionsNeverReturnBlobs Should the driver always treat data from
functions returning BLOBs as Strings - specifically to work around
dubious metadata returned by the server for GROUP BY clauses?
false 5.0.8
generateSimpleParameterMetadata Should the driver generate
simplified parameter metadata for PreparedStatements when no
metadata is available either because the server couldn't support
preparing the statement, or server-side prepared statements are
disabled? false 5.0.5
ignoreNonTxTables Ignore non-transactional table warning for
rollback? (defaults to 'false'). false 3.0.9
jdbcCompliantTruncation Should the driver throw
java.sql.DataTruncation exceptions when data is truncated as is
required by the JDBC specification when connected to a server that
supports warnings (MySQL 4.1.0 and newer)? This property has no
effect if the server sql-mode includes STRICT_TRANS_TABLES. true
3.1.2
maxRows The maximum number of rows to return (0, the default means
return all rows). -1 all versions
netTimeoutForStreamingResults What value should the driver
automatically set the server setting 'net_write_timeout' to when
the streaming result sets feature is in use? (value has unit of
seconds, the value '0' means the driver will not try and adjust
this value) 600 5.1.0
noAccessToProcedureBodies When determining procedure parameter
types for CallableStatements, and the connected user can't access
procedure bodies through "SHOW CREATE PROCEDURE" or select on
mysql.proc should the driver instead create basic metadata (all
parameters reported as IN VARCHARs, but allowing
registerOutParameter() to be called on them anyway) instead of
throwing an exception? false 5.0.3
noDatetimeStringSync Don't ensure that
ResultSet.getDatetimeType().toString().equals(ResultSet.getString(
)) false 3.1.7
noTimezoneConversionForTimeType Don't convert TIME values using
the server timezone if 'useTimezone'='true' false 5.0.0
nullCatalogMeansCurrent When DatabaseMetadataMethods ask for a
'catalog' parameter, does the value null mean use the current
catalog? (this is not JDBC-compliant, but follows legacy behavior
from earlier versions of the driver) true 3.1.8
nullNamePatternMatchesAll Should DatabaseMetaData methods that
accept *pattern parameters treat null the same as '%' (this is not
JDBC-compliant, however older versions of the driver accepted this
departure from the specification) true 3.1.8
overrideSupportsIntegrityEnhancementFacility Should the driver
return "true" for
DatabaseMetaData.supportsIntegrityEnhancementFacility() even if
the database doesn't support it to workaround applications that
require this method to return "true" to signal support of foreign
keys, even though the SQL specification states that this facility
contains much more than just foreign key support (one such
application being OpenOffice)? false 3.1.12
padCharsWithSpace If a result set column has the CHAR type and the
value does not fill the amount of characters specified in the DDL
for the column, should the driver pad the remaining characters
with space (for ANSI compliance)? false 5.0.6
pedantic Follow the JDBC spec to the letter. false 3.0.0
pinGlobalTxToPhysicalConnection When using XAConnections, should
the driver ensure that operations on a given XID are always routed
to the same physical connection? This allows the XAConnection to
support "XA START ... JOIN" after "XA END" has been called false
5.0.1
populateInsertRowWithDefaultValues When using ResultSets that are
CONCUR_UPDATABLE, should the driver pre-populate the "insert" row
with default values from the DDL for the table used in the query
so those values are immediately available for ResultSet accessors?
This functionality requires a call to the database for metadata
each time a result set of this type is created. If disabled (the
default), the default values will be populated by the an internal
call to refreshRow() which pulls back default values and/or values
changed by triggers. false 5.0.5
processEscapeCodesForPrepStmts Should the driver process escape
codes in queries that are prepared? true 3.1.12
relaxAutoCommit If the version of MySQL the driver connects to
does not support transactions, still allow calls to commit(),
rollback() and setAutoCommit() (true/false, defaults to 'false')?
false 2.0.13
retainStatementAfterResultSetClose Should the driver retain the
Statement reference in a ResultSet after ResultSet.close() has
been called. This is not JDBC-compliant after JDBC-4.0. false
3.1.11
rollbackOnPooledClose Should the driver issue a rollback() when
the logical connection in a pool is closed? true 3.0.15
runningCTS13 Enables workarounds for bugs in Sun's JDBC compliance
testsuite version 1.3 false 3.1.7
serverTimezone Override detection/mapping of timezone. Used when
timezone from server doesn't map to Java timezone 3.0.2
statementInterceptors A comma-delimited list of classes that
implement "com.mysql.jdbc.StatementInterceptor" that should be
placed "in between" query execution to influence the results.
StatementInterceptors are "chainable", the results returned by the
"current" interceptor will be passed on to the next in in the
chain, from left-to-right order, as specified in this property.
5.1.1
strictFloatingPoint Used only in older versions of compliance test
false 3.0.0
strictUpdates Should the driver do strict checking (all primary
keys selected) of updatable result sets (true, false, defaults to
'true')? true 3.0.4
tinyInt1isBit Should the driver treat the datatype TINYINT(1) as
the BIT type (because the server silently converts BIT ->
TINYINT(1) when creating tables)? true 3.0.16
transformedBitIsBoolean If the driver converts TINYINT(1) to a
different type, should it use BOOLEAN instead of BIT for future
compatibility with MySQL-5.0, as MySQL-5.0 has a BIT type? false
3.1.9
treatUtilDateAsTimestamp Should the driver treat java.util.Date as
a TIMESTAMP for the purposes of PreparedStatement.setObject()?
true 5.0.5
ultraDevHack Create PreparedStatements for prepareCall() when
required, because UltraDev is broken and issues a prepareCall()
for _all_ statements? (true/false, defaults to 'false') false
2.0.3
useGmtMillisForDatetimes Convert between session timezone and GMT
before creating Date and Timestamp instances (value of "false" is
legacy behavior, "true" leads to more JDBC-compliant behavior.
false 3.1.12
useHostsInPrivileges Add '@hostname' to users in
DatabaseMetaData.getColumn/TablePrivileges() (true/false),
defaults to 'true'. true 3.0.2
useInformationSchema When connected to MySQL-5.0.7 or newer,
should the driver use the INFORMATION_SCHEMA to derive information
used by DatabaseMetaData? false 5.0.0
useJDBCCompliantTimezoneShift Should the driver use JDBC-compliant
rules when converting TIME/TIMESTAMP/DATETIME values' timezone
information for those JDBC arguments which take a
java.util.Calendar argument? (Notice that this option is exclusive
of the "useTimezone=true" configuration option.) false 5.0.0
useOldAliasMetadataBehavior Should the driver use the legacy
behavior for "AS" clauses on columns and tables, and only return
aliases (if any) for ResultSetMetaData.getColumnName() or
ResultSetMetaData.getTableName() rather than the original
column/table name? false 5.0.4
useOldUTF8Behavior Use the UTF-8 behavior the driver did when
communicating with 4.0 and older servers false 3.1.6
useOnlyServerErrorMessages Don't prepend 'standard' SQLState error
messages to error messages returned by the server. true 3.0.15
useSSPSCompatibleTimezoneShift If migrating from an environment
that was using server-side prepared statements, and the
configuration property "useJDBCCompliantTimeZoneShift" set to
"true", use compatible behavior when not using server-side
prepared statements when sending TIMESTAMP values to the MySQL
server. false 5.0.5
useServerPrepStmts Use server-side prepared statements if the
server supports them? false 3.1.0
useSqlStateCodes Use SQL Standard state codes instead of 'legacy'
X/Open/SQL state codes (true/false), default is 'true' true 3.1.3
useStreamLengthsInPrepStmts Honor stream length parameter in
PreparedStatement/ResultSet.setXXXStream() method calls
(true/false, defaults to 'true')? true 3.0.2
useTimezone Convert time/date types between client and server
timezones (true/false, defaults to 'false')? false 3.0.2
useUnbufferedInput Don't use BufferedInputStream for reading data
from the server true 3.0.11
yearIsDateType Should the JDBC driver treat the MySQL type "YEAR"
as a java.sql.Date, or as a SHORT? true 3.1.9
zeroDateTimeBehavior What should happen when the driver encounters
DATETIME values that are composed entirely of zeroes (used by
MySQL to represent invalid dates)? Valid values are "exception",
"round" and "convertToNull". exception 3.1.4
Connector/J also supports access to MySQL via named pipes on
Windows NT/2000/XP using the NamedPipeSocketFactory as a
plugin-socket factory via the socketFactory property. If you don't
use a namedPipePath property, the default of '\\.\pipe\MySQL' will
be used. If you use the NamedPipeSocketFactory, the hostname and
port number values in the JDBC url will be ignored. You can enable
this feature using:
socketFactory=com.mysql.jdbc.NamedPipeSocketFactory
Named pipes only work when connecting to a MySQL server on the
same physical machine as the one the JDBC driver is being used on.
In simple performance tests, it appears that named pipe access is
between 30%-50% faster than the standard TCP/IP access.
You can create your own socket factories by following the example
code in com.mysql.jdbc.NamedPipeSocketFactory, or
com.mysql.jdbc.StandardSocketFactory.
4.2. JDBC API Implementation Notes
MySQL Connector/J passes all of the tests in the
publicly-available version of Sun's JDBC compliance test suite.
However, in many places the JDBC specification is vague about how
certain functionality should be implemented, or the specification
allows leeway in implementation.
This section gives details on a interface-by-interface level about
how certain implementation decisions may affect how you use MySQL
Connector/J.
* Blob
Starting with Connector/J version 3.1.0, you can emulate Blobs
with locators by adding the property 'emulateLocators=true' to
your JDBC URL. Using this method, the driver will delay
loading the actual Blob data until you retrieve the other data
and then use retrieval methods (getInputStream(), getBytes(),
and so forth) on the blob data stream.
For this to work, you must use a column alias with the value
of the column to the actual name of the Blob, for example:
SELECT id, 'data' as blob_data from blobtable
For this to work, you must also follow follow these rules:
+ The SELECT must also reference only one table, the table
must have a primary key.
+ The SELECT must alias the original blob column name,
specified as a string, to an alternate name.
+ The SELECT must cover all columns that make up the
primary key.
The Blob implementation does not allow in-place modification
(they are copies, as reported by the
DatabaseMetaData.locatorsUpdateCopies() method). Because of
this, you should use the corresponding
PreparedStatement.setBlob() or ResultSet.updateBlob() (in the
case of updatable result sets) methods to save changes back to
the database.
MySQL Enterprise MySQL Enterprise subscribers will find more
information about type conversion in the Knowledge Base
article, Type Conversions Supported by MySQL Connector/J
(https://kb.mysql.com/view.php?id=4929). To subscribe to MySQL
Enterprise see
http://www.mysql.com/products/enterprise/advisors.html.
* CallableStatement
Starting with Connector/J 3.1.1, stored procedures are
supported when connecting to MySQL version 5.0 or newer via
the CallableStatement interface. Currently, the
getParameterMetaData() method of CallableStatement is not
supported.
* Clob
The Clob implementation does not allow in-place modification
(they are copies, as reported by the
DatabaseMetaData.locatorsUpdateCopies() method). Because of
this, you should use the PreparedStatement.setClob() method to
save changes back to the database. The JDBC API does not have
a ResultSet.updateClob() method.
* Connection
Unlike older versions of MM.MySQL the isClosed() method does
not ping the server to determine if it is alive. In accordance
with the JDBC specification, it only returns true if closed()
has been called on the connection. If you need to determine if
the connection is still valid, you should issue a simple
query, such as SELECT 1. The driver will throw an exception if
the connection is no longer valid.
* DatabaseMetaData
Foreign Key information (getImportedKeys()/getExportedKeys()
and getCrossReference()) is only available from InnoDB tables.
However, the driver uses SHOW CREATE TABLE to retrieve this
information, so when other storage engines support foreign
keys, the driver will transparently support them as well.
* PreparedStatement
PreparedStatements are implemented by the driver, as MySQL
does not have a prepared statement feature. Because of this,
the driver does not implement getParameterMetaData() or
getMetaData() as it would require the driver to have a
complete SQL parser in the client.
Starting with version 3.1.0 MySQL Connector/J, server-side
prepared statements and binary-encoded result sets are used
when the server supports them.
Take care when using a server-side prepared statement with
large parameters that are set via setBinaryStream(),
setAsciiStream(), setUnicodeStream(), setBlob(), or setClob().
If you want to re-execute the statement with any large
parameter changed to a non-large parameter, it is necessary to
call clearParameters() and set all parameters again. The
reason for this is as follows:
+ During both server-side prepared statements and
client-side emulation, large data is exchanged only when
PreparedStatement.execute() is called.
+ Once that has been done, the stream used to read the data
on the client side is closed (as per the JDBC spec), and
can't be read from again.
+ If a parameter changes from large to non-large, the
driver must reset the server-side state of the prepared
statement to allow the parameter that is being changed to
take the place of the prior large value. This removes all
of the large data that has already been sent to the
server, thus requiring the data to be re-sent, via the
setBinaryStream(), setAsciiStream(), setUnicodeStream(),
setBlob() or setClob() methods.
Consequently, if you want to change the type of a parameter to
a non-large one, you must call clearParameters() and set all
parameters of the prepared statement again before it can be
re-executed.
* ResultSet
By default, ResultSets are completely retrieved and stored in
memory. In most cases this is the most efficient way to
operate, and due to the design of the MySQL network protocol
is easier to implement. If you are working with ResultSets
that have a large number of rows or large values, and can not
allocate heap space in your JVM for the memory required, you
can tell the driver to stream the results back one row at a
time.
To enable this functionality, you need to create a Statement
instance in the following manner:
stmt = conn.createStatement(java.sql.ResultSet.TYPE_FORWARD_ONLY,
java.sql.ResultSet.CONCUR_READ_ONLY);
stmt.setFetchSize(Integer.MIN_VALUE);
The combination of a forward-only, read-only result set, with
a fetch size of Integer.MIN_VALUE serves as a signal to the
driver to stream result sets row-by-row. After this any result
sets created with the statement will be retrieved row-by-row.
There are some caveats with this approach. You will have to
read all of the rows in the result set (or close it) before
you can issue any other queries on the connection, or an
exception will be thrown.
The earliest the locks these statements hold can be released
(whether they be MyISAM table-level locks or row-level locks
in some other storage engine such as InnoDB) is when the
statement completes.
If the statement is within scope of a transaction, then locks
are released when the transaction completes (which implies
that the statement needs to complete first). As with most
other databases, statements are not complete until all the
results pending on the statement are read or the active result
set for the statement is closed.
Therefore, if using streaming results, you should process them
as quickly as possible if you want to maintain concurrent
access to the tables referenced by the statement producing the
result set.
* ResultSetMetaData
The isAutoIncrement() method only works when using MySQL
servers 4.0 and newer.
* Statement
When using versions of the JDBC driver earlier than 3.2.1, and
connected to server versions earlier than 5.0.3, the
setFetchSize() method has no effect, other than to toggle
result set streaming as described above.
Connector/J 5.0.0 and later include support for both
Statement.cancel() and Statement.setQueryTimeout(). Both
require MySQL 5.0.0 or newer server, and require a separate
connection to issue the KILL QUERY statement. In the case of
setQueryTimeout(), the implementation creates an additional
thread to handle the timeout functionality.
Note
Failures to cancel the statement for setQueryTimeout() may
manifest themselves as RuntimeException rather than failing
silently, as there is currently no way to unblock the thread
that is executing the query being cancelled due to timeout
expiration and have it throw the exception instead.
MySQL does not support SQL cursors, and the JDBC driver
doesn't emulate them, so "setCursorName()" has no effect.
Connector/J 5.1.3 and later include two additional methods:
+ setLocalInfileInputStream() sets an InputStream instance
that will be used to send data to the MySQL server for a
LOAD DATA LOCAL INFILE statement rather than a
FileInputStream or URLInputStream that represents the
path given as an argument to the statement.
This stream will be read to completion upon execution of
a LOAD DATA LOCAL INFILE statement, and will
automatically be closed by the driver, so it needs to be
reset before each call to execute*() that would cause the
MySQL server to request data to fulfill the request for
LOAD DATA LOCAL INFILE.
If this value is set to NULL, the driver will revert to
using a FileInputStream or URLInputStream as required.
+ getLocalInfileInputStream() returns the InputStream
instance that will be used to send data in response to a
LOAD DATA LOCAL INFILE statement.
This method returns NULL if no such stream has been set
via setLocalInfileInputStream().
4.3. Java, JDBC and MySQL Types
MySQL Connector/J is flexible in the way it handles conversions
between MySQL data types and Java data types.
In general, any MySQL data type can be converted to a
java.lang.String, and any numerical type can be converted to any
of the Java numerical types, although round-off, overflow, or loss
of precision may occur.
Starting with Connector/J 3.1.0, the JDBC driver will issue
warnings or throw DataTruncation exceptions as is required by the
JDBC specification unless the connection was configured not to do
so by using the property jdbcCompliantTruncation and setting it to
false.
The conversions that are always guaranteed to work are listed in
the following table:
Connection Properties - Miscellaneous.
These MySQL Data Types Can always be converted to these Java types
CHAR, VARCHAR, BLOB, TEXT, ENUM, and SET java.lang.String,
java.io.InputStream, java.io.Reader, java.sql.Blob, java.sql.Clob
FLOAT, REAL, DOUBLE PRECISION, NUMERIC, DECIMAL, TINYINT,
SMALLINT, MEDIUMINT, INTEGER, BIGINT java.lang.String,
java.lang.Short, java.lang.Integer, java.lang.Long,
java.lang.Double, java.math.BigDecimal
DATE, TIME, DATETIME, TIMESTAMP java.lang.String, java.sql.Date,
java.sql.Timestamp
Note
Round-off, overflow or loss of precision may occur if you choose a
Java numeric data type that has less precision or capacity than
the MySQL data type you are converting to/from.
The ResultSet.getObject() method uses the type conversions between
MySQL and Java types, following the JDBC specification where
appropriate. The value returned by
ResultSetMetaData.GetColumnClassName() is also shown below. For
more information on the java.sql.Types classes see Java 2 Platform
Types
(http://java.sun.com/j2se/1.4.2/docs/api/java/sql/Types.html).
MySQL Types to Java Types for ResultSet.getObject().
MySQL Type Name Return value of GetColumnClassName Returned as
Java Class
BIT(1) (new in MySQL-5.0) BIT java.lang.Boolean
BIT( > 1) (new in MySQL-5.0) BIT byte[]
TINYINT TINYINT java.lang.Boolean if the configuration property
tinyInt1isBit is set to true (the default) and the storage size is
1, or java.lang.Integer if not.
BOOL, BOOLEAN TINYINT See TINYINT, above as these are aliases for
TINYINT(1), currently.
SMALLINT[(M)] [UNSIGNED] SMALLINT [UNSIGNED] java.lang.Integer
(regardless if UNSIGNED or not)
MEDIUMINT[(M)] [UNSIGNED] MEDIUMINT [UNSIGNED] java.lang.Integer,
if UNSIGNED java.lang.Long (C/J 3.1 and earlier), or
java.lang.Integer for C/J 5.0 and later
INT,INTEGER[(M)] [UNSIGNED] INTEGER [UNSIGNED] java.lang.Integer,
if UNSIGNED java.lang.Long
BIGINT[(M)] [UNSIGNED] BIGINT [UNSIGNED] java.lang.Long, if
UNSIGNED java.math.BigInteger
FLOAT[(M,D)] FLOAT java.lang.Float
DOUBLE[(M,B)] DOUBLE java.lang.Double
DECIMAL[(M[,D])] DECIMAL java.math.BigDecimal
DATE DATE java.sql.Date
DATETIME DATETIME java.sql.Timestamp
TIMESTAMP[(M)] TIMESTAMP java.sql.Timestamp
TIME TIME java.sql.Time
YEAR[(2|4)] YEAR If yearIsDateType configuration property is set
to false, then the returned object type is java.sql.Short. If set
to true (the default) then an object of type java.sql.Date (with
the date set to January 1st, at midnight).
CHAR(M) CHAR java.lang.String (unless the character set for the
column is BINARY, then byte[] is returned.
VARCHAR(M) [BINARY] VARCHAR java.lang.String (unless the character
set for the column is BINARY, then byte[] is returned.
BINARY(M) BINARY byte[]
VARBINARY(M) VARBINARY byte[]
TINYBLOB TINYBLOB byte[]
TINYTEXT VARCHAR java.lang.String
BLOB BLOB byte[]
TEXT VARCHAR java.lang.String
MEDIUMBLOB MEDIUMBLOB byte[]
MEDIUMTEXT VARCHAR java.lang.String
LONGBLOB LONGBLOB byte[]
LONGTEXT VARCHAR java.lang.String
ENUM('value1','value2',...) CHAR java.lang.String
SET('value1','value2',...) CHAR java.lang.String
4.4. Using Character Sets and Unicode
All strings sent from the JDBC driver to the server are converted
automatically from native Java Unicode form to the client
character encoding, including all queries sent via
Statement.execute(), Statement.executeUpdate(),
Statement.executeQuery() as well as all PreparedStatement and
CallableStatement parameters with the exclusion of parameters set
using setBytes(), setBinaryStream(), setAsciiStream(),
setUnicodeStream() and setBlob().
Prior to MySQL Server 4.1, Connector/J supported a single
character encoding per connection, which could either be
automatically detected from the server configuration, or could be
configured by the user through the useUnicode and
characterEncoding properties.
Starting with MySQL Server 4.1, Connector/J supports a single
character encoding between client and server, and any number of
character encodings for data returned by the server to the client
in ResultSets.
The character encoding between client and server is automatically
detected upon connection. The encoding used by the driver is
specified on the server via the character_set system variable for
server versions older than 4.1.0 and character_set_server for
server versions 4.1.0 and newer. For more information, see Server
Character Set and Collation
(http://dev.mysql.com/doc/refman/4.1/en/charset-server.html).
To override the automatically-detected encoding on the client
side, use the characterEncoding property in the URL used to
connect to the server.
When specifying character encodings on the client side, Java-style
names should be used. The following table lists Java-style names
for MySQL character sets:
MySQL to Java Encoding Name Translations.
MySQL Character Set Name Java-Style Character Encoding Name
ascii US-ASCII
big5 Big5
gbk GBK
sjis SJIS (or Cp932 or MS932 for MySQL Server < 4.1.11)
cp932 Cp932 or MS932 (MySQL Server > 4.1.11)
gb2312 EUC_CN
ujis EUC_JP
euckr EUC_KR
latin1 ISO8859_1
latin2 ISO8859_2
greek ISO8859_7
hebrew ISO8859_8
cp866 Cp866
tis620 TIS620
cp1250 Cp1250
cp1251 Cp1251
cp1257 Cp1257
macroman MacRoman
macce MacCentralEurope
utf8 UTF-8
ucs2 UnicodeBig
Warning
Do not issue the query 'set names' with Connector/J, as the driver
will not detect that the character set has changed, and will
continue to use the character set detected during the initial
connection setup.
To allow multiple character sets to be sent from the client, the
UTF-8 encoding should be used, either by configuring utf8 as the
default server character set, or by configuring the JDBC driver to
use UTF-8 through the characterEncoding property.
4.5. Connecting Securely Using SSL
SSL in MySQL Connector/J encrypts all data (other than the initial
handshake) between the JDBC driver and the server. The performance
penalty for enabling SSL is an increase in query processing time
between 35% and 50%, depending on the size of the query, and the
amount of data it returns.
For SSL Support to work, you must have the following:
* A JDK that includes JSSE (Java Secure Sockets Extension), like
JDK-1.4.1 or newer. SSL does not currently work with a JDK
that you can add JSSE to, like JDK-1.2.x or JDK-1.3.x due to
the following JSSE bug:
http://developer.java.sun.com/developer/bugParade/bugs/4273544
.html
* A MySQL server that supports SSL and has been compiled and
configured to do so, which is MySQL-4.0.4 or later, see Using
Secure Connections
(http://dev.mysql.com/doc/refman/4.1/en/secure-connections.htm
l), for more information.
* A client certificate (covered later in this section)
The system works through two Java truststore files, one file
contains the certificate information for the server (truststore in
the examples below). The other file contains the certificate for
the client (keystore in the examples below). All Java truststore
files are password protected by supplying a suitable password to
the keytool when you create the files. You need the file names and
associated passwords to create an SSL connection.
You will first need to import the MySQL server CA Certificate into
a Java truststore. A sample MySQL server CA Certificate is located
in the SSL subdirectory of the MySQL source distribution. This is
what SSL will use to determine if you are communicating with a
secure MySQL server. Alternatively, use the CA Certificate that
you have generated or been provided with by your SSL provider.
To use Java's keytool to create a truststore in the current
directory , and import the server's CA certificate (cacert.pem),
you can do the following (assuming that keytool is in your path.
The keytool should be located in the bin subdirectory of your JDK
or JRE):
shell> keytool -import -alias mysqlServerCACert \
-file cacert.pem -keystore truststo
re
You will need to enter the password when prompted for the keystore
file. Interaction with keytool will look like this:
Enter keystore password: *********
Owner: EMAILADDRESS=walrus@example.com, CN=Walrus,
O=MySQL AB, L=Orenburg, ST=Some-State, C=RU
Issuer: EMAILADDRESS=walrus@example.com, CN=Walrus,
O=MySQL AB, L=Orenburg, ST=Some-State, C=RU
Serial number: 0
Valid from:
Fri Aug 02 16:55:53 CDT 2002 until: Sat Aug 02 16:55:53 CDT 2003
Certificate fingerprints:
MD5: 61:91:A0:F2:03:07:61:7A:81:38:66:DA:19:C4:8D:AB
SHA1: 25:77:41:05:D5:AD:99:8C:14:8C:CA:68:9C:2F:B8:89:C3:34:4D:6C
Trust this certificate? [no]: yes
Certificate was added to keystore
You then have two options, you can either import the client
certificate that matches the CA certificate you just imported, or
you can create a new client certificate.
To import an existing certificate, the certificate should be in
DER format. You can use openssl to convert an existing certificate
into the new format. For example:
shell> openssl x509 -outform DER -in client-cert.pem -out client.cert
You now need to import the converted certificate into your
keystore using keytool:
shell> keytool -import -file client.cert -keystore keystore -alias my
sqlClientCertificate
To generate your own client certificate, use keytool to create a
suitable certificate and add it to the keystore file:
shell> keytool -genkey -keyalg rsa \
-alias mysqlClientCertificate -keystore keystore
Keytool will prompt you for the following information, and create
a keystore named keystore in the current directory.
You should respond with information that is appropriate for your
situation:
Enter keystore password: *********
What is your first and last name?
[Unknown]: Matthews
What is the name of your organizational unit?
[Unknown]: Software Development
What is the name of your organization?
[Unknown]: MySQL AB
What is the name of your City or Locality?
[Unknown]: Flossmoor
What is the name of your State or Province?
[Unknown]: IL
What is the two-letter country code for this unit?
[Unknown]: US
Is <CN=Matthews, OU=Software Development, O=MySQL AB,
L=Flossmoor, ST=IL, C=US> correct?
[no]: y
Enter key password for <mysqlClientCertificate>
(RETURN if same as keystore password):
Finally, to get JSSE to use the keystore and truststore that you
have generated, you need to set the following system properties
when you start your JVM, replacing path_to_keystore_file with the
full path to the keystore file you created,
path_to_truststore_file with the path to the truststore file you
created, and using the appropriate password values for each
property. You can do this either on the command line:
-Djavax.net.ssl.keyStore=path_to_keystore_file
-Djavax.net.ssl.keyStorePassword=password
-Djavax.net.ssl.trustStore=path_to_truststore_file
-Djavax.net.ssl.trustStorePassword=password
Or you can set the values directly within the application:
System.setProperty("javax.net.ssl.keyStore","path_to_keystore_file")
;
System.setProperty("javax.net.ssl.keyStorePassword","password");
System.setProperty("javax.net.ssl.trustStore","path_to_truststore_fil
e");
System.setProperty("javax.net.ssl.trustStorePassword","password");
You will also need to set useSSL to true in your connection
parameters for MySQL Connector/J, either by adding useSSL=true to
your URL, or by setting the property useSSL to true in the
java.util.Properties instance you pass to
DriverManager.getConnection().
You can test that SSL is working by turning on JSSE debugging (as
detailed below), and look for the following key events:
...
*** ClientHello, v3.1
RandomCookie: GMT: 1018531834 bytes = { 199, 148, 180, 215, 74, 12,
»
54, 244, 0, 168, 55, 103, 215, 64, 16, 138, 225, 190, 132, 153, 2,
»
217, 219, 239, 202, 19, 121, 78 }
Session ID: {}
Cipher Suites: { 0, 5, 0, 4, 0, 9, 0, 10, 0, 18, 0, 19, 0, 3, 0, 17
}
Compression Methods: { 0 }
***
[write] MD5 and SHA1 hashes: len = 59
0000: 01 00 00 37 03 01 3D B6 90 FA C7 94 B4 D7 4A 0C ...7..=.......
J.
0010: 36 F4 00 A8 37 67 D7 40 10 8A E1 BE 84 99 02 D9 6...7g.@......
..
0020: DB EF CA 13 79 4E 00 00 10 00 05 00 04 00 09 00 ....yN........
..
0030: 0A 00 12 00 13 00 03 00 11 01 00 ...........
main, WRITE: SSL v3.1 Handshake, length = 59
main, READ: SSL v3.1 Handshake, length = 74
*** ServerHello, v3.1
RandomCookie: GMT: 1018577560 bytes = { 116, 50, 4, 103, 25, 100, 58
, »
202, 79, 185, 178, 100, 215, 66, 254, 21, 83, 187, 190, 42, 170, 3
, »
132, 110, 82, 148, 160, 92 }
Session ID: {163, 227, 84, 53, 81, 127, 252, 254, 178, 179, 68, 63,
»
182, 158, 30, 11, 150, 79, 170, 76, 255, 92, 15, 226, 24, 17, 177,
»
219, 158, 177, 187, 143}
Cipher Suite: { 0, 5 }
Compression Method: 0
***
%% Created: [Session-1, SSL_RSA_WITH_RC4_128_SHA]
** SSL_RSA_WITH_RC4_128_SHA
[read] MD5 and SHA1 hashes: len = 74
0000: 02 00 00 46 03 01 3D B6 43 98 74 32 04 67 19 64 ...F..=.C.t2.g
.d
0010: 3A CA 4F B9 B2 64 D7 42 FE 15 53 BB BE 2A AA 03 :.O..d.B..S..*
..
0020: 84 6E 52 94 A0 5C 20 A3 E3 54 35 51 7F FC FE B2 .nR..\ ..T5Q..
..
0030: B3 44 3F B6 9E 1E 0B 96 4F AA 4C FF 5C 0F E2 18 .D?.....O.L.\.
..
0040: 11 B1 DB 9E B1 BB 8F 00 05 00 ..........
main, READ: SSL v3.1 Handshake, length = 1712
...
JSSE provides debugging (to STDOUT) when you set the following
system property: -Djavax.net.debug=all This will tell you what
keystores and truststores are being used, as well as what is going
on during the SSL handshake and certificate exchange. It will be
helpful when trying to determine what is not working when trying
to get an SSL connection to happen.
4.6. Using Master/Slave Replication with ReplicationConnection
Starting with Connector/J 3.1.7, we've made available a variant of
the driver that will automatically send queries to a read/write
master, or a failover or round-robin loadbalanced set of slaves
based on the state of Connection.getReadOnly() .
An application signals that it wants a transaction to be read-only
by calling Connection.setReadOnly(true), this replication-aware
connection will use one of the slave connections, which are
load-balanced per-vm using a round-robin scheme (a given
connection is sticky to a slave unless that slave is removed from
service). If you have a write transaction, or if you have a read
that is time-sensitive (remember, replication in MySQL is
asynchronous), set the connection to be not read-only, by calling
Connection.setReadOnly(false) and the driver will ensure that
further calls are sent to the master MySQL server. The driver
takes care of propagating the current state of autocommit,
isolation level, and catalog between all of the connections that
it uses to accomplish this load balancing functionality.
To enable this functionality, use the "
com.mysql.jdbc.ReplicationDriver " class when configuring your
application server's connection pool or when creating an instance
of a JDBC driver for your standalone application. Because it
accepts the same URL format as the standard MySQL JDBC driver,
ReplicationDriver does not currently work with
java.sql.DriverManager -based connection creation unless it is the
only MySQL JDBC driver registered with the DriverManager .
Here is a short, simple example of how ReplicationDriver might be
used in a standalone application.
import java.sql.Connection;
import java.sql.ResultSet;
import java.util.Properties;
import com.mysql.jdbc.ReplicationDriver;
public class ReplicationDriverDemo {
public static void main(String[] args) throws Exception {
ReplicationDriver driver = new ReplicationDriver();
Properties props = new Properties();
// We want this for failover on the slaves
props.put("autoReconnect", "true");
// We want to load balance between the slaves
props.put("roundRobinLoadBalance", "true");
props.put("user", "foo");
props.put("password", "bar");
//
// Looks like a normal MySQL JDBC url, with a
// comma-separated list of hosts, the first
// being the 'master', the rest being any number
// of slaves that the driver will load balance against
//
Connection conn =
driver.connect("jdbc:mysql://master,slave1,slave2,slave3/test
",
props);
//
// Perform read/write work on the master
// by setting the read-only flag to "false"
//
conn.setReadOnly(false);
conn.setAutoCommit(false);
conn.createStatement().executeUpdate("UPDATE some_table ....");
conn.commit();
//
// Now, do a query from a slave, the driver automatically picks o
ne
// from the list
//
conn.setReadOnly(true);
ResultSet rs =
conn.createStatement().executeQuery("SELECT a,b FROM alt_table"
);
.......
}
}
You may also want to investigate the Load Balancing JDBC Pool
(lbpol) tool, which provides a wrapper around the standard JDBC
driver and allows you to use DB connection pools that includes
checks for system failures and uneven load distribution. For more
information, see Load Balancing JDBC Pool (lbpool)
(http://code.tailrank.com/lbpool).
4.7. Mapping MySQL Error Numbers to SQLStates
The table below provides a mapping of the MySQL Error Numbers to
SQL States
Table 4.1. Mapping of MySQL Error Numbers to SQLStates
MySQL Error Number MySQL Error Name Legacy (X/Open) SQLState SQL
Standard SQLState
1022 ER_DUP_KEY S1000 23000
1037 ER_OUTOFMEMORY S1001 HY001
1038 ER_OUT_OF_SORTMEMORY S1001 HY001
1040 ER_CON_COUNT_ERROR 08004 08004
1042 ER_BAD_HOST_ERROR 08004 08S01
1043 ER_HANDSHAKE_ERROR 08004 08S01
1044 ER_DBACCESS_DENIED_ERROR S1000 42000
1045 ER_ACCESS_DENIED_ERROR 28000 28000
1047 ER_UNKNOWN_COM_ERROR 08S01 HY000
1050 ER_TABLE_EXISTS_ERROR S1000 42S01
1051 ER_BAD_TABLE_ERROR 42S02 42S02
1052 ER_NON_UNIQ_ERROR S1000 23000
1053 ER_SERVER_SHUTDOWN S1000 08S01
1054 ER_BAD_FIELD_ERROR S0022 42S22
1055 ER_WRONG_FIELD_WITH_GROUP S1009 42000
1056 ER_WRONG_GROUP_FIELD S1009 42000
1057 ER_WRONG_SUM_SELECT S1009 42000
1058 ER_WRONG_VALUE_COUNT 21S01 21S01
1059 ER_TOO_LONG_IDENT S1009 42000
1060 ER_DUP_FIELDNAME S1009 42S21
1061 ER_DUP_KEYNAME S1009 42000
1062 ER_DUP_ENTRY S1009 23000
1063 ER_WRONG_FIELD_SPEC S1009 42000
1064 ER_PARSE_ERROR 42000 42000
1065 ER_EMPTY_QUERY 42000 42000
1066 ER_NONUNIQ_TABLE S1009 42000
1067 ER_INVALID_DEFAULT S1009 42000
1068 ER_MULTIPLE_PRI_KEY S1009 42000
1069 ER_TOO_MANY_KEYS S1009 42000
1070 ER_TOO_MANY_KEY_PARTS S1009 42000
1071 ER_TOO_LONG_KEY S1009 42000
1072 ER_KEY_COLUMN_DOES_NOT_EXITS S1009 42000
1073 ER_BLOB_USED_AS_KEY S1009 42000
1074 ER_TOO_BIG_FIELDLENGTH S1009 42000
1075 ER_WRONG_AUTO_KEY S1009 42000
1080 ER_FORCING_CLOSE S1000 08S01
1081 ER_IPSOCK_ERROR 08S01 08S01
1082 ER_NO_SUCH_INDEX S1009 42S12
1083 ER_WRONG_FIELD_TERMINATORS S1009 42000
1084 ER_BLOBS_AND_NO_TERMINATED S1009 42000
1090 ER_CANT_REMOVE_ALL_FIELDS S1000 42000
1091 ER_CANT_DROP_FIELD_OR_KEY S1000 42000
1101 ER_BLOB_CANT_HAVE_DEFAULT S1000 42000
1102 ER_WRONG_DB_NAME S1000 42000
1103 ER_WRONG_TABLE_NAME S1000 42000
1104 ER_TOO_BIG_SELECT S1000 42000
1106 ER_UNKNOWN_PROCEDURE S1000 42000
1107 ER_WRONG_PARAMCOUNT_TO_PROCEDURE S1000 42000
1109 ER_UNKNOWN_TABLE S1000 42S02
1110 ER_FIELD_SPECIFIED_TWICE S1000 42000
1112 ER_UNSUPPORTED_EXTENSION S1000 42000
1113 ER_TABLE_MUST_HAVE_COLUMNS S1000 42000
1115 ER_UNKNOWN_CHARACTER_SET S1000 42000
1118 ER_TOO_BIG_ROWSIZE S1000 42000
1120 ER_WRONG_OUTER_JOIN S1000 42000
1121 ER_NULL_COLUMN_IN_INDEX S1000 42000
1129 ER_HOST_IS_BLOCKED 08004 HY000
1130 ER_HOST_NOT_PRIVILEGED 08004 HY000
1131 ER_PASSWORD_ANONYMOUS_USER S1000 42000
1132 ER_PASSWORD_NOT_ALLOWED S1000 42000
1133 ER_PASSWORD_NO_MATCH S1000 42000
1136 ER_WRONG_VALUE_COUNT_ON_ROW S1000 21S01
1138 ER_INVALID_USE_OF_NULL S1000 42000
1139 ER_REGEXP_ERROR S1000 42000
1140 ER_MIX_OF_GROUP_FUNC_AND_FIELDS S1000 42000
1141 ER_NONEXISTING_GRANT S1000 42000
1142 ER_TABLEACCESS_DENIED_ERROR S1000 42000
1143 ER_COLUMNACCESS_DENIED_ERROR S1000 42000
1144 ER_ILLEGAL_GRANT_FOR_TABLE S1000 42000
1145 ER_GRANT_WRONG_HOST_OR_USER S1000 42000
1146 ER_NO_SUCH_TABLE S1000 42S02
1147 ER_NONEXISTING_TABLE_GRANT S1000 42000
1148 ER_NOT_ALLOWED_COMMAND S1000 42000
1149 ER_SYNTAX_ERROR S1000 42000
1152 ER_ABORTING_CONNECTION S1000 08S01
1153 ER_NET_PACKET_TOO_LARGE S1000 08S01
1154 ER_NET_READ_ERROR_FROM_PIPE S1000 08S01
1155 ER_NET_FCNTL_ERROR S1000 08S01
1156 ER_NET_PACKETS_OUT_OF_ORDER S1000 08S01
1157 ER_NET_UNCOMPRESS_ERROR S1000 08S01
1158 ER_NET_READ_ERROR S1000 08S01
1159 ER_NET_READ_INTERRUPTED S1000 08S01
1160 ER_NET_ERROR_ON_WRITE S1000 08S01
1161 ER_NET_WRITE_INTERRUPTED S1000 08S01
1162 ER_TOO_LONG_STRING S1000 42000
1163 ER_TABLE_CANT_HANDLE_BLOB S1000 42000
1164 ER_TABLE_CANT_HANDLE_AUTO_INCREMENT S1000 42000
1166 ER_WRONG_COLUMN_NAME S1000 42000
1167 ER_WRONG_KEY_COLUMN S1000 42000
1169 ER_DUP_UNIQUE S1000 23000
1170 ER_BLOB_KEY_WITHOUT_LENGTH S1000 42000
1171 ER_PRIMARY_CANT_HAVE_NULL S1000 42000
1172 ER_TOO_MANY_ROWS S1000 42000
1173 ER_REQUIRES_PRIMARY_KEY S1000 42000
1177 ER_CHECK_NO_SUCH_TABLE S1000 42000
1178 ER_CHECK_NOT_IMPLEMENTED S1000 42000
1179 ER_CANT_DO_THIS_DURING_AN_TRANSACTION S1000 25000
1184 ER_NEW_ABORTING_CONNECTION S1000 08S01
1189 ER_MASTER_NET_READ S1000 08S01
1190 ER_MASTER_NET_WRITE S1000 08S01
1203 ER_TOO_MANY_USER_CONNECTIONS S1000 42000
1205 ER_LOCK_WAIT_TIMEOUT 41000 41000
1207 ER_READ_ONLY_TRANSACTION S1000 25000
1211 ER_NO_PERMISSION_TO_CREATE_USER S1000 42000
1213 ER_LOCK_DEADLOCK 41000 40001
1216 ER_NO_REFERENCED_ROW S1000 23000
1217 ER_ROW_IS_REFERENCED S1000 23000
1218 ER_CONNECT_TO_MASTER S1000 08S01
1222 ER_WRONG_NUMBER_OF_COLUMNS_IN_SELECT S1000 21000
1226 ER_USER_LIMIT_REACHED S1000 42000
1230 ER_NO_DEFAULT S1000 42000
1231 ER_WRONG_VALUE_FOR_VAR S1000 42000
1232 ER_WRONG_TYPE_FOR_VAR S1000 42000
1234 ER_CANT_USE_OPTION_HERE S1000 42000
1235 ER_NOT_SUPPORTED_YET S1000 42000
1239 ER_WRONG_FK_DEF S1000 42000
1241 ER_OPERAND_COLUMNS S1000 21000
1242 ER_SUBQUERY_NO_1_ROW S1000 21000
1247 ER_ILLEGAL_REFERENCE S1000 42S22
1248 ER_DERIVED_MUST_HAVE_ALIAS S1000 42000
1249 ER_SELECT_REDUCED S1000 01000
1250 ER_TABLENAME_NOT_ALLOWED_HERE S1000 42000
1251 ER_NOT_SUPPORTED_AUTH_MODE S1000 08004
1252 ER_SPATIAL_CANT_HAVE_NULL S1000 42000
1253 ER_COLLATION_CHARSET_MISMATCH S1000 42000
1261 ER_WARN_TOO_FEW_RECORDS S1000 01000
1262 ER_WARN_TOO_MANY_RECORDS S1000 01000
1263 ER_WARN_NULL_TO_NOTNULL S1000 01000
1264 ER_WARN_DATA_OUT_OF_RANGE S1000 01000
1265 ER_WARN_DATA_TRUNCATED S1000 01000
1280 ER_WRONG_NAME_FOR_INDEX S1000 42000
1281 ER_WRONG_NAME_FOR_CATALOG S1000 42000
1286 ER_UNKNOWN_STORAGE_ENGINE S1000 42000
Chapter 5. Connector/J Notes and Tips
5.1. Basic JDBC Concepts
This section provides some general JDBC background.
5.1.1. Connecting to MySQL Using the DriverManager Interface
When you are using JDBC outside of an application server, the
DriverManager class manages the establishment of Connections.
The DriverManager needs to be told which JDBC drivers it should
try to make Connections with. The easiest way to do this is to use
Class.forName() on the class that implements the java.sql.Driver
interface. With MySQL Connector/J, the name of this class is
com.mysql.jdbc.Driver. With this method, you could use an external
configuration file to supply the driver class name and driver
parameters to use when connecting to a database.
The following section of Java code shows how you might register
MySQL Connector/J from the main() method of your application:
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
// Notice, do not import com.mysql.jdbc.*
// or you will have problems!
public class LoadDriver {
public static void main(String[] args) {
try {
// The newInstance() call is a work around for some
// broken Java implementations
Class.forName("com.mysql.jdbc.Driver").newInstance();
} catch (Exception ex) {
// handle the error
}
}
After the driver has been registered with the DriverManager, you
can obtain a Connection instance that is connected to a particular
database by calling DriverManager.getConnection():
Example 5.1. Obtaining a connection from the DriverManager
This example shows how you can obtain a Connection instance from
the DriverManager. There are a few different signatures for the
getConnection() method. You should see the API documentation that
comes with your JDK for more specific information on how to use
them.
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
...
try {
Connection conn =
DriverManager.getConnection("jdbc:mysql://localhost/test?" +
"user=monty&password=greatsqldb");
// Do something with the Connection
...
} catch (SQLException ex) {
// handle any errors
System.out.println("SQLException: " + ex.getMessage());
System.out.println("SQLState: " + ex.getSQLState());
System.out.println("VendorError: " + ex.getErrorCode());
}
Once a Connection is established, it can be used to create
Statement and PreparedStatement objects, as well as retrieve
metadata about the database. This is explained in the following
sections.
5.1.2. Using Statements to Execute SQL
Statement objects allow you to execute basic SQL queries and
retrieve the results through the ResultSet class which is
described later.
To create a Statement instance, you call the createStatement()
method on the Connection object you have retrieved via one of the
DriverManager.getConnection() or DataSource.getConnection()
methods described earlier.
Once you have a Statement instance, you can execute a SELECT query
by calling the executeQuery(String) method with the SQL you want
to use.
To update data in the database, use the executeUpdate(String SQL)
method. This method returns the number of rows affected by the
update statement.
If you don't know ahead of time whether the SQL statement will be
a SELECT or an UPDATE/INSERT, then you can use the execute(String
SQL) method. This method will return true if the SQL query was a
SELECT, or false if it was an UPDATE, INSERT, or DELETE statement.
If the statement was a SELECT query, you can retrieve the results
by calling the getResultSet() method. If the statement was an
UPDATE, INSERT, or DELETE statement, you can retrieve the affected
rows count by calling getUpdateCount() on the Statement instance.
Example 5.2. Using java.sql.Statement to execute a SELECT query
// assume that conn is an already created JDBC connection
Statement stmt = null;
ResultSet rs = null;
try {
stmt = conn.createStatement();
rs = stmt.executeQuery("SELECT foo FROM bar");
// or alternatively, if you don't know ahead of time that
// the query will be a SELECT...
if (stmt.execute("SELECT foo FROM bar")) {
rs = stmt.getResultSet();
}
// Now do something with the ResultSet ....
} finally {
// it is a good idea to release
// resources in a finally{} block
// in reverse-order of their creation
// if they are no-longer needed
if (rs != null) {
try {
rs.close();
} catch (SQLException sqlEx) { // ignore }
rs = null;
}
if (stmt != null) {
try {
stmt.close();
} catch (SQLException sqlEx) { // ignore }
stmt = null;
}
}
5.1.3. Using CallableStatements to Execute Stored Procedures
Starting with MySQL server version 5.0 when used with Connector/J
3.1.1 or newer, the java.sql.CallableStatement interface is fully
implemented with the exception of the getParameterMetaData()
method.
For more information on MySQL stored procedures, please refer to
http://dev.mysql.com/doc/mysql/en/stored-procedures.html.
Connector/J exposes stored procedure functionality through JDBC's
CallableStatement interface.
Note
Current versions of MySQL server do not return enough information
for the JDBC driver to provide result set metadata for callable
statements. This means that when using CallableStatement,
ResultSetMetaData may return NULL.
The following example shows a stored procedure that returns the
value of inOutParam incremented by 1, and the string passed in via
inputParam as a ResultSet:
Example 5.3. Stored Procedures
CREATE PROCEDURE demoSp(IN inputParam VARCHAR(255), \
INOUT inOutParam INT)
BEGIN
DECLARE z INT;
SET z = inOutParam + 1;
SET inOutParam = z;
SELECT inputParam;
SELECT CONCAT('zyxw', inputParam);
END
To use the demoSp procedure with Connector/J, follow these steps:
1. Prepare the callable statement by using
Connection.prepareCall() .
Notice that you have to use JDBC escape syntax, and that the
parentheses surrounding the parameter placeholders are not
optional:
Example 5.4. Using Connection.prepareCall()
import java.sql.CallableStatement;
...
//
// Prepare a call to the stored procedure 'demoSp'
// with two parameters
//
// Notice the use of JDBC-escape syntax ({call ...})
//
CallableStatement cStmt = conn.prepareCall("{call demoSp(?, ?)}")
;
cStmt.setString(1, "abcdefg");
Note
Connection.prepareCall() is an expensive method, due to the
metadata retrieval that the driver performs to support output
parameters. For performance reasons, you should try to
minimize unnecessary calls to Connection.prepareCall() by
reusing CallableStatement instances in your code.
2. Register the output parameters (if any exist)
To retrieve the values of output parameters (parameters
specified as OUT or INOUT when you created the stored
procedure), JDBC requires that they be specified before
statement execution using the various
registerOutputParameter() methods in the CallableStatement
interface:
Example 5.5. Registering output parameters
import java.sql.Types;
...
//
// Connector/J supports both named and indexed
// output parameters. You can register output
// parameters using either method, as well
// as retrieve output parameters using either
// method, regardless of what method was
// used to register them.
//
// The following examples show how to use
// the various methods of registering
// output parameters (you should of course
// use only one registration per parameter).
//
//
// Registers the second parameter as output, and
// uses the type 'INTEGER' for values returned from
// getObject()
//
cStmt.registerOutParameter(2, Types.INTEGER);
//
// Registers the named parameter 'inOutParam', and
// uses the type 'INTEGER' for values returned from
// getObject()
//
cStmt.registerOutParameter("inOutParam", Types.INTEGER);
...
3. Set the input parameters (if any exist)
Input and in/out parameters are set as for PreparedStatement
objects. However, CallableStatement also supports setting
parameters by name:
Example 5.6. Setting CallableStatement input parameters
...
//
// Set a parameter by index
//
cStmt.setString(1, "abcdefg");
//
// Alternatively, set a parameter using
// the parameter name
//
cStmt.setString("inputParameter", "abcdefg");
//
// Set the 'in/out' parameter using an index
//
cStmt.setInt(2, 1);
//
// Alternatively, set the 'in/out' parameter
// by name
//
cStmt.setInt("inOutParam", 1);
...
4. Execute the CallableStatement, and retrieve any result sets or
output parameters.
Although CallableStatement supports calling any of the
Statement execute methods (executeUpdate(), executeQuery() or
execute()), the most flexible method to call is execute(), as
you do not need to know ahead of time if the stored procedure
returns result sets:
Example 5.7. Retrieving results and output parameter values
...
boolean hadResults = cStmt.execute();
//
// Process all returned result sets
//
while (hadResults) {
ResultSet rs = cStmt.getResultSet();
// process result set
...
hadResults = cStmt.getMoreResults();
}
//
// Retrieve output parameters
//
// Connector/J supports both index-based and
// name-based retrieval
//
int outputValue = cStmt.getInt(2); // index-based
outputValue = cStmt.getInt("inOutParam"); // name-based
...
5.1.4. Retrieving AUTO_INCREMENT Column Values
Before version 3.0 of the JDBC API, there was no standard way of
retrieving key values from databases that supported auto increment
or identity columns. With older JDBC drivers for MySQL, you could
always use a MySQL-specific method on the Statement interface, or
issue the query SELECT LAST_INSERT_ID() after issuing an INSERT to
a table that had an AUTO_INCREMENT key. Using the MySQL-specific
method call isn't portable, and issuing a SELECT to get the
AUTO_INCREMENT key's value requires another round-trip to the
database, which isn't as efficient as possible. The following code
snippets demonstrate the three different ways to retrieve
AUTO_INCREMENT values. First, we demonstrate the use of the new
JDBC-3.0 method getGeneratedKeys() which is now the preferred
method to use if you need to retrieve AUTO_INCREMENT keys and have
access to JDBC-3.0. The second example shows how you can retrieve
the same value using a standard SELECT LAST_INSERT_ID() query. The
final example shows how updatable result sets can retrieve the
AUTO_INCREMENT value when using the insertRow() method.
Example 5.8. Retrieving AUTO_INCREMENT column values using
Statement.getGeneratedKeys()
Statement stmt = null;
ResultSet rs = null;
try {
//
// Create a Statement instance that we can use for
// 'normal' result sets assuming you have a
// Connection 'conn' to a MySQL database already
// available
stmt = conn.createStatement(java.sql.ResultSet.TYPE_FORWARD_ONLY,
java.sql.ResultSet.CONCUR_UPDATABLE);
//
// Issue the DDL queries for the table for this example
//
stmt.executeUpdate("DROP TABLE IF EXISTS autoIncTutorial");
stmt.executeUpdate(
"CREATE TABLE autoIncTutorial ("
+ "priKey INT NOT NULL AUTO_INCREMENT, "
+ "dataField VARCHAR(64), PRIMARY KEY (priKey))");
//
// Insert one row that will generate an AUTO INCREMENT
// key in the 'priKey' field
//
stmt.executeUpdate(
"INSERT INTO autoIncTutorial (dataField) "
+ "values ('Can I Get the Auto Increment Field?')",
Statement.RETURN_GENERATED_KEYS);
//
// Example of using Statement.getGeneratedKeys()
// to retrieve the value of an auto-increment
// value
//
int autoIncKeyFromApi = -1;
rs = stmt.getGeneratedKeys();
if (rs.next()) {
autoIncKeyFromApi = rs.getInt(1);
} else {
// throw an exception from here
}
rs.close();
rs = null;
System.out.println("Key returned from getGeneratedKeys():"
+ autoIncKeyFromApi);
} finally {
if (rs != null) {
try {
rs.close();
} catch (SQLException ex) {
// ignore
}
}
if (stmt != null) {
try {
stmt.close();
} catch (SQLException ex) {
// ignore
}
}
}
Example 5.9. Retrieving AUTO_INCREMENT column values using SELECT
LAST_INSERT_ID()
Statement stmt = null;
ResultSet rs = null;
try {
//
// Create a Statement instance that we can use for
// 'normal' result sets.
stmt = conn.createStatement();
//
// Issue the DDL queries for the table for this example
//
stmt.executeUpdate("DROP TABLE IF EXISTS autoIncTutorial");
stmt.executeUpdate(
"CREATE TABLE autoIncTutorial ("
+ "priKey INT NOT NULL AUTO_INCREMENT, "
+ "dataField VARCHAR(64), PRIMARY KEY (priKey))");
//
// Insert one row that will generate an AUTO INCREMENT
// key in the 'priKey' field
//
stmt.executeUpdate(
"INSERT INTO autoIncTutorial (dataField) "
+ "values ('Can I Get the Auto Increment Field?')");
//
// Use the MySQL LAST_INSERT_ID()
// function to do the same thing as getGeneratedKeys()
//
int autoIncKeyFromFunc = -1;
rs = stmt.executeQuery("SELECT LAST_INSERT_ID()");
if (rs.next()) {
autoIncKeyFromFunc = rs.getInt(1);
} else {
// throw an exception from here
}
rs.close();
System.out.println("Key returned from " +
"'SELECT LAST_INSERT_ID()': " +
autoIncKeyFromFunc);
} finally {
if (rs != null) {
try {
rs.close();
} catch (SQLException ex) {
// ignore
}
}
if (stmt != null) {
try {
stmt.close();
} catch (SQLException ex) {
// ignore
}
}
}
Example 5.10. Retrieving AUTO_INCREMENT column values in Updatable
ResultSets
Statement stmt = null;
ResultSet rs = null;
try {
//
// Create a Statement instance that we can use for
// 'normal' result sets as well as an 'updatable'
// one, assuming you have a Connection 'conn' to
// a MySQL database already available
//
stmt = conn.createStatement(java.sql.ResultSet.TYPE_FORWARD_ONLY,
java.sql.ResultSet.CONCUR_UPDATABLE);
//
// Issue the DDL queries for the table for this example
//
stmt.executeUpdate("DROP TABLE IF EXISTS autoIncTutorial");
stmt.executeUpdate(
"CREATE TABLE autoIncTutorial ("
+ "priKey INT NOT NULL AUTO_INCREMENT, "
+ "dataField VARCHAR(64), PRIMARY KEY (priKey))");
//
// Example of retrieving an AUTO INCREMENT key
// from an updatable result set
//
rs = stmt.executeQuery("SELECT priKey, dataField "
+ "FROM autoIncTutorial");
rs.moveToInsertRow();
rs.updateString("dataField", "AUTO INCREMENT here?");
rs.insertRow();
//
// the driver adds rows at the end
//
rs.last();
//
// We should now be on the row we just inserted
//
int autoIncKeyFromRS = rs.getInt("priKey");
rs.close();
rs = null;
System.out.println("Key returned for inserted row: "
+ autoIncKeyFromRS);
} finally {
if (rs != null) {
try {
rs.close();
} catch (SQLException ex) {
// ignore
}
}
if (stmt != null) {
try {
stmt.close();
} catch (SQLException ex) {
// ignore
}
}
}
When you run the preceding example code, you should get the
following output: Key returned from getGeneratedKeys(): 1 Key
returned from SELECT LAST_INSERT_ID(): 1 Key returned for inserted
row: 2 You should be aware, that at times, it can be tricky to use
the SELECT LAST_INSERT_ID() query, as that function's value is
scoped to a connection. So, if some other query happens on the
same connection, the value will be overwritten. On the other hand,
the getGeneratedKeys() method is scoped by the Statement instance,
so it can be used even if other queries happen on the same
connection, but not on the same Statement instance.
5.2. Using Connector/J with J2EE and Other Java Frameworks
This section describes how to use Connector/J in several contexts.
5.2.1. General J2EE Concepts
This section provides general background on J2EE concepts that
pertain to use of Connector/J.
5.2.1.1. Understanding Connection Pooling
Connection pooling is a technique of creating and managing a pool
of connections that are ready for use by any thread that needs
them.
This technique of pooling connections is based on the fact that
most applications only need a thread to have access to a JDBC
connection when they are actively processing a transaction, which
usually take only milliseconds to complete. When not processing a
transaction, the connection would otherwise sit idle. Instead,
connection pooling allows the idle connection to be used by some
other thread to do useful work.
In practice, when a thread needs to do work against a MySQL or
other database with JDBC, it requests a connection from the pool.
When the thread is finished using the connection, it returns it to
the pool, so that it may be used by any other threads that want to
use it.
When the connection is loaned out from the pool, it is used
exclusively by the thread that requested it. From a programming
point of view, it is the same as if your thread called
DriverManager.getConnection() every time it needed a JDBC
connection, however with connection pooling, your thread may end
up using either a new, or already-existing connection.
Connection pooling can greatly increase the performance of your
Java application, while reducing overall resource usage. The main
benefits to connection pooling are:
* Reduced connection creation time
Although this is not usually an issue with the quick
connection setup that MySQL offers compared to other
databases, creating new JDBC connections still incurs
networking and JDBC driver overhead that will be avoided if
connections are recycled.
* Simplified programming model
When using connection pooling, each individual thread can act
as though it has created its own JDBC connection, allowing you
to use straight-forward JDBC programming techniques.
* Controlled resource usage
If you don't use connection pooling, and instead create a new
connection every time a thread needs one, your application's
resource usage can be quite wasteful and lead to unpredictable
behavior under load.
Remember that each connection to MySQL has overhead (memory, CPU,
context switches, and so forth) on both the client and server
side. Every connection limits how many resources there are
available to your application as well as the MySQL server. Many of
these resources will be used whether or not the connection is
actually doing any useful work!
Connection pools can be tuned to maximize performance, while
keeping resource utilization below the point where your
application will start to fail rather than just run slower.
Luckily, Sun has standardized the concept of connection pooling in
JDBC through the JDBC-2.0 Optional interfaces, and all major
application servers have implementations of these APIs that work
fine with MySQL Connector/J.
Generally, you configure a connection pool in your application
server configuration files, and access it via the Java Naming and
Directory Interface (JNDI). The following code shows how you might
use a connection pool from an application deployed in a J2EE
application server:
Example 5.11. Using a connection pool with a J2EE application
server
import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import javax.naming.InitialContext;
import javax.sql.DataSource;
public class MyServletJspOrEjb {
public void doSomething() throws Exception {
/*
* Create a JNDI Initial context to be able to
* lookup the DataSource
*
* In production-level code, this should be cached as
* an instance or static variable, as it can
* be quite expensive to create a JNDI context.
*
* Note: This code only works when you are using servlets
* or EJBs in a J2EE application server. If you are
* using connection pooling in standalone Java code, you
* will have to create/configure datasources using whatever
* mechanisms your particular connection pooling library
* provides.
*/
InitialContext ctx = new InitialContext();
/*
* Lookup the DataSource, which will be backed by a pool
* that the application server provides. DataSource instance
s
* are also a good candidate for caching as an instance
* variable, as JNDI lookups can be expensive as well.
*/
DataSource ds =
(DataSource)ctx.lookup("java:comp/env/jdbc/MySQLDB");
/*
* The following code is what would actually be in your
* Servlet, JSP or EJB 'service' method...where you need
* to work with a JDBC connection.
*/
Connection conn = null;
Statement stmt = null;
try {
conn = ds.getConnection();
/*
* Now, use normal JDBC programming to work with
* MySQL, making sure to close each resource when you're
* finished with it, which allows the connection pool
* resources to be recovered as quickly as possible
*/
stmt = conn.createStatement();
stmt.execute("SOME SQL QUERY");
stmt.close();
stmt = null;
conn.close();
conn = null;
} finally {
/*
* close any jdbc instances here that weren't
* explicitly closed during normal code path, so
* that we don't 'leak' resources...
*/
if (stmt != null) {
try {
stmt.close();
} catch (sqlexception sqlex) {
// ignore -- as we can't do anything about it her
e
}
stmt = null;
}
if (conn != null) {
try {
conn.close();
} catch (sqlexception sqlex) {
// ignore -- as we can't do anything about it her
e
}
conn = null;
}
}
}
}
As shown in the example above, after obtaining the JNDI
InitialContext, and looking up the DataSource, the rest of the
code should look familiar to anyone who has done JDBC programming
in the past.
The most important thing to remember when using connection pooling
is to make sure that no matter what happens in your code
(exceptions, flow-of-control, and so forth), connections, and
anything created by them (such as statements or result sets) are
closed, so that they may be re-used, otherwise they will be
stranded, which in the best case means that the MySQL server
resources they represent (such as buffers, locks, or sockets) may
be tied up for some time, or worst case, may be tied up forever.
What's the Best Size for my Connection Pool?
As with all other configuration rules-of-thumb, the answer is: it
depends. Although the optimal size depends on anticipated load and
average database transaction time, the optimum connection pool
size is smaller than you might expect. If you take Sun's Java
Petstore blueprint application for example, a connection pool of
15-20 connections can serve a relatively moderate load (600
concurrent users) using MySQL and Tomcat with response times that
are acceptable.
To correctly size a connection pool for your application, you
should create load test scripts with tools such as Apache JMeter
or The Grinder, and load test your application.
An easy way to determine a starting point is to configure your
connection pool's maximum number of connections to be unbounded,
run a load test, and measure the largest amount of concurrently
used connections. You can then work backward from there to
determine what values of minimum and maximum pooled connections
give the best performance for your particular application.
5.2.2. Using Connector/J with Tomcat
The following instructions are based on the instructions for
Tomcat-5.x, available at
http://tomcat.apache.org/tomcat-5.5-doc/jndi-datasource-examples-h
owto.html which is current at the time this document was written.
First, install the .jar file that comes with Connector/J in
$CATALINA_HOME/common/lib so that it is available to all
applications installed in the container.
Next, Configure the JNDI DataSource by adding a declaration
resource to $CATALINA_HOME/conf/server.xml in the context that
defines your web application:
<Context ....>
...
<Resource name="jdbc/MySQLDB"
auth="Container"
type="javax.sql.DataSource"/>
<!-- The name you used above, must match _exactly_ here!
The connection pool will be bound into JNDI with the name
"java:/comp/env/jdbc/MySQLDB"
-->
<ResourceParams name="jdbc/MySQLDB">
<parameter>
<name>factory</name>
<value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
</parameter>
<!-- Don't set this any higher than max_connections on your
MySQL server, usually this should be a 10 or a few 10's
of connections, not hundreds or thousands -->
<parameter>
<name>maxActive</name>
<value>10</value>
</parameter>
<!-- You don't want to many idle connections hanging around
if you can avoid it, only enough to soak up a spike in
the load -->
<parameter>
<name>maxIdle</name>
<value>5</value>
</parameter>
<!-- Don't use autoReconnect=true, it's going away eventually
and it's a crutch for older connection pools that couldn't
test connections. You need to decide whether your applicatio
n
is supposed to deal with SQLExceptions (hint, it should), an
d
how much of a performance penalty you're willing to pay
to ensure 'freshness' of the connection -->
<parameter>
<name>validationQuery</name>
<value>SELECT 1</value>
</parameter>
<!-- The most conservative approach is to test connections
before they're given to your application. For most applicatio
ns
this is okay, the query used above is very small and takes
no real server resources to process, other than the time used
to traverse the network.
If you have a high-load application you'll need to rely on
something else. -->
<parameter>
<name>testOnBorrow</name>
<value>true</value>
</parameter>
<!-- Otherwise, or in addition to testOnBorrow, you can test
while connections are sitting idle -->
<parameter>
<name>testWhileIdle</name>
<value>true</value>
</parameter>
<!-- You have to set this value, otherwise even though
you've asked connections to be tested while idle,
the idle evicter thread will never run -->
<parameter>
<name>timeBetweenEvictionRunsMillis</name>
<value>10000</value>
</parameter>
<!-- Don't allow connections to hang out idle too long,
never longer than what wait_timeout is set to on the
server...A few minutes or even fraction of a minute
is sometimes okay here, it depends on your application
and how much spikey load it will see -->
<parameter>
<name>minEvictableIdleTimeMillis</name>
<value>60000</value>
</parameter>
<!-- Username and password used when connecting to MySQL -->
<parameter>
<name>username</name>
<value>someuser</value>
</parameter>
<parameter>
<name>password</name>
<value>somepass</value>
</parameter>
<!-- Class name for the Connector/J driver -->
<parameter>
<name>driverClassName</name>
<value>com.mysql.jdbc.Driver</value>
</parameter>
<!-- The JDBC connection url for connecting to MySQL, notice
that if you want to pass any other MySQL-specific parameters
you should pass them here in the URL, setting them using the
parameter tags above will have no effect, you will also
need to use & to separate parameter values as the
ampersand is a reserved character in XML -->
<parameter>
<name>url</name>
<value>jdbc:mysql://localhost:3306/test</value>
</parameter>
</ResourceParams>
</Context>
In general, you should follow the installation instructions that
come with your version of Tomcat, as the way you configure
datasources in Tomcat changes from time-to-time, and unfortunately
if you use the wrong syntax in your XML file, you will most likely
end up with an exception similar to the following:
Error: java.sql.SQLException: Cannot load JDBC driver class 'null ' S
QL
state: null
5.2.3. Using Connector/J with JBoss
These instructions cover JBoss-4.x. To make the JDBC driver
classes available to the application server, copy the .jar file
that comes with Connector/J to the lib directory for your server
configuration (which is usually called default). Then, in the same
configuration directory, in the subdirectory named deploy, create
a datasource configuration file that ends with "-ds.xml", which
tells JBoss to deploy this file as a JDBC Datasource. The file
should have the following contents:
<datasources>
<local-tx-datasource>
<!-- This connection pool will be bound into JNDI with the na
me
"java:/MySQLDB" -->
<jndi-name>MySQLDB</jndi-name>
<connection-url>jdbc:mysql://localhost:3306/dbname</connectio
n-url>
<driver-class>com.mysql.jdbc.Driver</driver-class>
<user-name>user</user-name>
<password>pass</password>
<min-pool-size>5</min-pool-size>
<!-- Don't set this any higher than max_connections on your
MySQL server, usually this should be a 10 or a few 10's
of connections, not hundreds or thousands -->
<max-pool-size>20</max-pool-size>
<!-- Don't allow connections to hang out idle too long,
never longer than what wait_timeout is set to on the
server...A few minutes is usually okay here,
it depends on your application
and how much spikey load it will see -->
<idle-timeout-minutes>5</idle-timeout-minutes>
<!-- If you're using Connector/J 3.1.8 or newer, you can use
our implementation of these to increase the robustness
of the connection pool. -->
<exception-sorter-class-name>
com.mysql.jdbc.integration.jboss.ExtendedMysqlExceptionSorter
</exception-sorter-class-name>
<valid-connection-checker-class-name>
com.mysql.jdbc.integration.jboss.MysqlValidConnectionChecker
</valid-connection-checker-class-name>
</local-tx-datasource>
</datasources>
5.2.4. Using Connector/J with Spring
The Spring Framework is a Java-based application framework
designed for assisting in application design by providing a way to
configure components. The technique used by Spring is a well known
design pattern called Dependency Injection (see Inversion of
Control Containers and the Dependency Injection pattern
(http://www.martinfowler.com/articles/injection.html)). This
article will focus on Java-oriented access to MySQL databases with
Spring 2.0. For those wondering, there is a .NET port of Spring
appropriately named Spring.NET.
Spring is not only a system for configuring components, but also
includes support for aspect oriented programming (AOP). This is
one of the main benefits and the foundation for Spring's resource
and transaction management. Spring also provides utilities for
integrating resource management with JDBC and Hibernate.
For the examples in this section the MySQL world sample database
will be used. The first task is to set up a MySQL data source
through Spring. Components within Spring use the "bean"
terminology. For example, to configure a connection to a MySQL
server supporting the world sample database you might use:
<util:map id="dbProps">
<entry key="db.driver" value="com.mysql.jdbc.Driver"/>
<entry key="db.jdbcurl" value="jdbc:mysql://localhost/world"/>
<entry key="db.username" value="myuser"/>
<entry key="db.password" value="mypass"/>
</util:map>
In the above example we are assigning values to properties that
will be used in the configuration. For the datasource
configuration:
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSo
urce">
<property name="driverClassName" value="${db.driver}"/>
<property name="url" value="${db.jdbcurl}"/>
<property name="username" value="${db.username}"/>
<property name="password" value="${db.password}"/>
</bean>
The placeholders are used to provide values for properties of this
bean. This means that you can specify all the properties of the
configuration in one place instead of entering the values for each
property on each bean. We do, however, need one more bean to pull
this all together. The last bean is responsible for actually
replacing the placeholders with the property values.
<bean
class="org.springframework.beans.factory.config.PropertyPlaceholderC
onfigurer">
<property name="properties" ref="dbProps"/>
</bean>
Now that we have our MySQL data source configured and ready to go,
we write some Java code to access it. The example below will
retrieve three random cities and their corresponding country using
the data source we configured with Spring.
// Create a new application context. this processes the Spring config
ApplicationContext ctx =
new ClassPathXmlApplicationContext("ex1appContext.xml");
// Retrieve the data source from the application context
DataSource ds = (DataSource) ctx.getBean("dataSource");
// Open a database connection using Spring's DataSourceUtils
Connection c = DataSourceUtils.getConnection(ds);
try {
// retrieve a list of three random cities
PreparedStatement ps = c.prepareStatement(
"select City.Name as 'City', Country.Name as 'Country' " +
"from City inner join Country on City.CountryCode = Country.C
ode " +
"order by rand() limit 3");
ResultSet rs = ps.executeQuery();
while(rs.next()) {
String city = rs.getString("City");
String country = rs.getString("Country");
System.out.printf("The city %s is in %s%n", city, country);
}
} catch (SQLException ex) {
// something has failed and we print a stack trace to analyse the
error
ex.printStackTrace();
// ignore failure closing connection
try { c.close(); } catch (SQLException e) { }
} finally {
// properly release our connection
DataSourceUtils.releaseConnection(c, ds);
}
This is very similar to normal JDBC access to MySQL with the main
difference being that we are using DataSourceUtils instead of the
DriverManager to create the connection.
While it may seem like a small difference, the implications are
somewhat far reaching. Spring manages this resource in a way
similar to a container managed data source in a J2EE application
server. When a connection is opened, it can be subsequently
accessed in other parts of the code if it is synchronized with a
transaction. This makes it possible to treat different parts of
your application as transactional instead of passing around a
database connection.
5.2.4.1. Using JdbcTemplate
Spring makes extensive use of the Template method design pattern
(see Template Method Pattern
(http://en.wikipedia.org/wiki/Template_method_pattern)). Our
immediate focus will be on the JdbcTemplate and related classes,
specifically NamedParameterJdbcTemplate. The template classes
handle obtaining and releasing a connection for data access when
one is needed.
The next example shows how to use NamedParameterJdbcTemplate
inside of a DAO (Data Access Object) class to retrieve a random
city given a country code.
public class Ex2JdbcDao {
/**
* Data source reference which will be provided by Spring.
*/
private DataSource dataSource;
/**
* Our query to find a random city given a country code. Notice
* the ":country" parameter towards the end. This is called a
* named parameter.
*/
private String queryString = "select Name from City " +
"where CountryCode = :country order by rand() limit 1";
/**
* Retrieve a random city using Spring JDBC access classes.
*/
public String getRandomCityByCountryCode(String cntryCode) {
// A template that allows using queries with named parameter
s
NamedParameterJdbcTemplate template =
new NamedParameterJdbcTemplate(dataSource);
// A java.util.Map is used to provide values for the paramet
ers
Map params = new HashMap();
params.put("country", cntryCode);
// We query for an Object and specify what class we are expe
cting
return (String)template.queryForObject(queryString, params,
String.class);
}
/**
* A JavaBean setter-style method to allow Spring to inject the da
ta source.
* @param dataSource
*/
public void setDataSource(DataSource dataSource) {
this.dataSource = dataSource;
}
}
The focus in the above code is on the getRandomCityByCountryCode()
method. We pass a country code and use the
NamedParameterJdbcTemplate to query for a city. The country code
is placed in a Map with the key "country", which is the parameter
is named in the SQL query.
To access this code, you need to configure it with Spring by
providing a reference to the data source.
<bean id="dao" class="code.Ex2JdbcDao">
<property name="dataSource" ref="dataSource"/>
</bean>
At this point, we can just grab a reference to the DAO from Spring
and call getRandomCityByCountryCode().
// Create the application context
ApplicationContext ctx =
new ClassPathXmlApplicationContext("ex2appContext.xml");
// Obtain a reference to our DAO
Ex2JdbcDao dao = (Ex2JdbcDao) ctx.getBean("dao");
String countryCode = "USA";
// Find a few random cities in the US
for(int i = 0; i < 4; ++i)
System.out.printf("A random city in %s is %s%n", countryCode,
dao.getRandomCityByCountryCode(countryCode));
This example shows how to use Spring's JDBC classes to completely
abstract away the use of traditional JDBC classes including
Connection and PreparedStatement.
5.2.4.2. Transactional JDBC Access
You might be wondering how we can add transactions into our code
if we don't deal directly with the JDBC classes. Spring provides a
transaction management package that not only replaces JDBC
transaction management, but also allows declarative transaction
management (configuration instead of code).
In order to use transactional database access, we will need to
change the storage engine of the tables in the world database. The
downloaded script explicitly creates MyISAM tables which do not
support transactional semantics. The InnoDB storage engine does
support transactions and this is what we will be using. We can
change the storage engine with the following statements.
ALTER TABLE City ENGINE=InnoDB;
ALTER TABLE Country ENGINE=InnoDB;
ALTER TABLE CountryLanguage ENGINE=InnoDB;
A good programming practice emphasized by Spring is separating
interfaces and implementations. What this means is that we can
create a Java interface and only use the operations on this
interface without any internal knowledge of what the actual
implementation is. We will let Spring manage the implementation
and with this it will manage the transactions for our
implementation.
First you create a simple interface:
public interface Ex3Dao {
Integer createCity(String name, String countryCode,
String district, Integer population);
}
This interface contains one method that will create a new city
record in the database and return the id of the new record. Next
you need to create an implementation of this interface.
public class Ex3DaoImpl implements Ex3Dao {
protected DataSource dataSource;
protected SqlUpdate updateQuery;
protected SqlFunction idQuery;
public Integer createCity(String name, String countryCode,
String district, Integer population) {
updateQuery.update(new Object[] { name, countryCode,
district, population });
return getLastId();
}
protected Integer getLastId() {
return idQuery.run();
}
}
You can see that we only operate on abstract query objects here
and don't deal directly with the JDBC API. Also, this is the
complete implementation. All of our transaction management will be
dealt with in the configuration. To get the configuration started,
we need to create the DAO.
<bean id="dao" class="code.Ex3DaoImpl">
<property name="dataSource" ref="dataSource"/>
<property name="updateQuery">...</property>
<property name="idQuery">...</property>
</bean>
Now you need to set up the transaction configuration. The first
thing you must do is create transaction manager to manage the data
source and a specification of what transaction properties are
required for for the dao methods.
<bean id="transactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionMan
ager">
<property name="dataSource" ref="dataSource"/>
</bean>
<tx:advice id="txAdvice" transaction-manager="transactionManager">
<tx:attributes>
<tx:method name="*"/>
</tx:attributes>
</tx:advice>
The preceding code creates a transaction manager that handles
transactions for the data source provided to it. The txAdvice uses
this transaction manager and the attributes specify to create a
transaction for all methods. Finally you need to apply this advice
with an AOP pointcut.
<aop:config>
<aop:pointcut id="daoMethods"
expression="execution(* code.Ex3Dao.*(..))"/>
<aop:advisor advice-ref="txAdvice" pointcut-ref="daoMethods"/>
</aop:config>
This basically says that all methods called on the Ex3Dao
interface will be wrapped in a transaction. To make use of this,
you only have to retrieve the dao from the application context and
call a method on the dao instance.
Ex3Dao dao = (Ex3Dao) ctx.getBean("dao");
Integer id = dao.createCity(name, countryCode, district, pop);
We can verify from this that there is no transaction management
happening in our Java code and it's all configured with Spring.
This is a very powerful notion and regarded as one of the most
beneficial features of Spring.
5.2.4.3. Connection Pooling
In many sitations, such as web applications, there will be a large
number of small database transactions. When this is the case, it
usually makes sense to create a pool of database connections
available for web requests as needed. Although MySQL does not
spawn an extra process when a connection is made, there is still a
small amount of overhead to create and set up the connection.
Pooling of connections also alleviates problems such as collecting
large amounts of sockets in the TIME_WAIT state.
Setting up pooling of MySQL connections with Spring is as simple
as changing the data source configuration in the application
context. There are a number of configurations that we can use. The
first example is based on the Jakarta Commons DBCP library
(http://jakarta.apache.org/commons/dbcp/). The example below
replaces the source configuration that was based on
DriverManagerDataSource with DBCP's BasicDataSource.
<bean id="dataSource" destroy-method="close"
class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName" value="${db.driver}"/>
<property name="url" value="${db.jdbcurl}"/>
<property name="username" value="${db.username}"/>
<property name="password" value="${db.password}"/>
<property name="initialSize" value="3"/>
</bean>
The configuration of the two solutions is very similar. The
difference is that DBCP will pool connections to the database
instead of creating a new connection every time one is requested.
We have also set a parameter here called initialSize. This tells
DBCP that we want three connections in the pool when it is
created.
Another way to configure connection pooling is to configure a data
source in our J2EE application server. Using JBoss as an example,
you can set up the MySQL connection pool by creating a file called
mysql-local-ds.xml and placing it in the server/default/deploy
directory in JBoss. Once we have this setup, we can use JNDI to
look it up. With Spring, this lookup is very simple. The data
source configuration looks like this.
<jee:jndi-lookup id="dataSource" jndi-name="java:MySQL_DS"/>
5.3. Common Problems and Solutions
There are a few issues that seem to be commonly encountered often
by users of MySQL Connector/J. This section deals with their
symptoms, and their resolutions.
Questions
* 6.3.1: When I try to connect to the database with MySQL
Connector/J, I get the following exception:
SQLException: Server configuration denies access to data source
SQLState: 08001
VendorError: 0
What's going on? I can connect just fine with the MySQL
command-line client.
* 6.3.2: My application throws an SQLException 'No Suitable
Driver'. Why is this happening?
* 6.3.3: I'm trying to use MySQL Connector/J in an applet or
application and I get an exception similar to:
SQLException: Cannot connect to MySQL server on host:3306.
Is there a MySQL server running on the machine/port you
are trying to connect to?
(java.security.AccessControlException)
SQLState: 08S01
VendorError: 0
* 6.3.4: I have a servlet/application that works fine for a day,
and then stops working overnight
* 6.3.5: I'm trying to use JDBC-2.0 updatable result sets, and I
get an exception saying my result set is not updatable.
* 6.3.6: I cannot connect to the MySQL server using Connector/J,
and I'm sure the connection paramters are correct.
* 6.3.7: I am trying to connect to my MySQL server within my
application, but I get the following error and stack trace:
java.net.SocketException
MESSAGE: Software caused connection abort: recv failed
STACKTRACE:
java.net.SocketException: Software caused connection abort: recv fail
ed
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(Unknown Source)
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1392)
at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:1414)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:625)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:1926)
at com.mysql.jdbc.Connection.<init>(Connection.java:452)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.j
ava:411)
* 6.3.8: My application is deployed through JBoss and I am using
transactions to handle the statements on the MySQL database.
Under heavy loads I am getting a error and stack trace, but
these only occur after a fixed period of heavy activity.
* 6.3.9: When using gcj an java.io.CharConversionException is
raised when working with certain character sequences.
* 6.3.10: Updating a table that contains a primary key that is
either FLOAT or compound primary key that uses FLOAT fails to
update the table and raises an exception.
Questions and Answers
6.3.1: When I try to connect to the database with MySQL
Connector/J, I get the following exception:
SQLException: Server configuration denies access to data source
SQLState: 08001
VendorError: 0
What's going on? I can connect just fine with the MySQL
command-line client.
MySQL Connector/J must use TCP/IP sockets to connect to MySQL, as
Java does not support Unix Domain Sockets. Therefore, when MySQL
Connector/J connects to MySQL, the security manager in MySQL
server will use its grant tables to determine whether the
connection should be allowed.
You must add the necessary security credentials to the MySQL
server for this to happen, using the GRANT statement to your MySQL
Server. See GRANT Syntax
(http://dev.mysql.com/doc/refman/4.1/en/grant.html), for more
information.
Note
Testing your connectivity with the mysql command-line client will
not work unless you add the --host flag, and use something other
than localhost for the host. The mysql command-line client will
use Unix domain sockets if you use the special hostname localhost.
If you are testing connectivity to localhost, use 127.0.0.1 as the
hostname instead.
Warning
Changing privileges and permissions improperly in MySQL can
potentially cause your server installation to not have optimal
security properties.
6.3.2: My application throws an SQLException 'No Suitable Driver'.
Why is this happening?
There are three possible causes for this error:
* The Connector/J driver is not in your CLASSPATH, see Chapter
2, "Connector/J Installation."
* The format of your connection URL is incorrect, or you are
referencing the wrong JDBC driver.
* When using DriverManager, the jdbc.drivers system property has
not been populated with the location of the Connector/J
driver.
6.3.3: I'm trying to use MySQL Connector/J in an applet or
application and I get an exception similar to:
SQLException: Cannot connect to MySQL server on host:3306.
Is there a MySQL server running on the machine/port you
are trying to connect to?
(java.security.AccessControlException)
SQLState: 08S01
VendorError: 0
Either you're running an Applet, your MySQL server has been
installed with the "--skip-networking" option set, or your MySQL
server has a firewall sitting in front of it.
Applets can only make network connections back to the machine that
runs the web server that served the .class files for the applet.
This means that MySQL must run on the same machine (or you must
have some sort of port re-direction) for this to work. This also
means that you will not be able to test applets from your local
file system, you must always deploy them to a web server.
MySQL Connector/J can only communicate with MySQL using TCP/IP, as
Java does not support Unix domain sockets. TCP/IP communication
with MySQL might be affected if MySQL was started with the
"--skip-networking" flag, or if it is firewalled.
If MySQL has been started with the "--skip-networking" option set
(the Debian Linux package of MySQL server does this for example),
you need to comment it out in the file /etc/mysql/my.cnf or
/etc/my.cnf. Of course your my.cnf file might also exist in the
data directory of your MySQL server, or anywhere else (depending
on how MySQL was compiled for your system). Binaries created by
MySQL AB always look in /etc/my.cnf and [datadir]/my.cnf. If your
MySQL server has been firewalled, you will need to have the
firewall configured to allow TCP/IP connections from the host
where your Java code is running to the MySQL server on the port
that MySQL is listening to (by default, 3306).
6.3.4: I have a servlet/application that works fine for a day, and
then stops working overnight
MySQL closes connections after 8 hours of inactivity. You either
need to use a connection pool that handles stale connections or
use the "autoReconnect" parameter (see Section 4.1,
"Driver/Datasource Class Names, URL Syntax and Configuration
Properties for Connector/J").
Also, you should be catching SQLExceptions in your application and
dealing with them, rather than propagating them all the way until
your application exits, this is just good programming practice.
MySQL Connector/J will set the SQLState (see
java.sql.SQLException.getSQLState() in your APIDOCS) to "08S01"
when it encounters network-connectivity issues during the
processing of a query. Your application code should then attempt
to re-connect to MySQL at this point.
The following (simplistic) example shows what code that can handle
these exceptions might look like:
Example 5.12. Example of transaction with retry logic
public void doBusinessOp() throws SQLException {
Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
//
// How many times do you want to retry the transaction
// (or at least _getting_ a connection)?
//
int retryCount = 5;
boolean transactionCompleted = false;
do {
try {
conn = getConnection(); // assume getting this from a
// javax.sql.DataSource, or the
// java.sql.DriverManager
conn.setAutoCommit(false);
//
// Okay, at this point, the 'retry-ability' of the
// transaction really depends on your application logic,
// whether or not you're using autocommit (in this case
// not), and whether you're using transacational storage
// engines
//
// For this example, we'll assume that it's _not_ safe
// to retry the entire transaction, so we set retry
// count to 0 at this point
//
// If you were using exclusively transaction-safe tables,
// or your application could recover from a connection go
ing
// bad in the middle of an operation, then you would not
// touch 'retryCount' here, and just let the loop repeat
// until retryCount == 0.
//
retryCount = 0;
stmt = conn.createStatement();
String query = "SELECT foo FROM bar ORDER BY baz";
rs = stmt.executeQuery(query);
while (rs.next()) {
}
rs.close();
rs = null;
stmt.close();
stmt = null;
conn.commit();
conn.close();
conn = null;
transactionCompleted = true;
} catch (SQLException sqlEx) {
//
// The two SQL states that are 'retry-able' are 08S01
// for a communications error, and 40001 for deadlock.
//
// Only retry if the error was due to a stale connection,
// communications problem or deadlock
//
String sqlState = sqlEx.getSQLState();
if ("08S01".equals(sqlState) || "40001".equals(sqlState))
{
retryCount--;
} else {
retryCount = 0;
}
} finally {
if (rs != null) {
try {
rs.close();
} catch (SQLException sqlEx) {
// You'd probably want to log this . . .
}
}
if (stmt != null) {
try {
stmt.close();
} catch (SQLException sqlEx) {
// You'd probably want to log this as well . . .
}
}
if (conn != null) {
try {
//
// If we got here, and conn is not null, the
// transaction should be rolled back, as not
// all work has been done
try {
conn.rollback();
} finally {
conn.close();
}
} catch (SQLException sqlEx) {
//
// If we got an exception here, something
// pretty serious is going on, so we better
// pass it up the stack, rather than just
// logging it. . .
throw sqlEx;
}
}
}
} while (!transactionCompleted && (retryCount > 0));
}
Note
Use of the autoReconnect option is not recommended because there
is no safe method of reconnecting to the MySQL server without
risking some corruption of the connection state or database state
information. Instead, you should use a connection pool which will
enable your application to connect to the MySQL server using an
available connection from the pool. The autoReconnect facility is
deprecated, and may be removed in a future release.
6.3.5: I'm trying to use JDBC-2.0 updatable result sets, and I get
an exception saying my result set is not updatable.
Because MySQL does not have row identifiers, MySQL Connector/J can
only update result sets that have come from queries on tables that
have at least one primary key, the query must select every primary
key and the query can only span one table (that is, no joins).
This is outlined in the JDBC specification.
Note that this issue only occurs when using updatable result sets,
and is caused because Connector/J is unable to guarantee that it
can identify the correct rows within the result set to be updated
without having a unique reference to each row. There is no
requirement to have a unique field on a table if you are using
UPDATE or DELETE statements on a table where you can individually
specify the criteria to be matched using a WHERE clause.
6.3.6: I cannot connect to the MySQL server using Connector/J, and
I'm sure the connection paramters are correct.
Make sure that the skip-networking option has not been enabled on
your server. Connector/J must be able to communicate with your
server over TCP/IP, named sockets are not supported. Also ensure
that you are not filtering connections through a Firewall or other
network security system. For more informaiton, see Can't connect
to [local] MySQL server
(http://dev.mysql.com/doc/refman/4.1/en/can-not-connect-to-server.
html).
6.3.7: I am trying to connect to my MySQL server within my
application, but I get the following error and stack trace:
java.net.SocketException
MESSAGE: Software caused connection abort: recv failed
STACKTRACE:
java.net.SocketException: Software caused connection abort: recv fail
ed
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(Unknown Source)
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1392)
at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:1414)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:625)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:1926)
at com.mysql.jdbc.Connection.<init>(Connection.java:452)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.j
ava:411)
The error probably indicates that you are using a older version of
the Connector/J JDBC driver (2.0.14 or 3.0.x) and you are trying
to connect to a MySQL server with version 4.1x or newer. The older
drivers are not compatible with 4.1 or newer of MySQL as they do
not support the newer authentication mechanisms.
It is likely that the older version of the Connector/J driver
exists within your application directory or your CLASSPATH
includes the older Connector/J package.
6.3.8: My application is deployed through JBoss and I am using
transactions to handle the statements on the MySQL database. Under
heavy loads I am getting a error and stack trace, but these only
occur after a fixed period of heavy activity.
This is a JBoss, not Connector/J, issue and is connected to the
use of transactions. Under heavy loads the time taken for
transactions to complete can increase, and the error is caused
because you have exceeded the predefined timeout.
You can increase the timeout value by setting the
TransactionTimeout attribute to the TransactionManagerService
within the /conf/jboss-service.xml file (pre-4.0.3) or
/deploy/jta-service.xml for JBoss 4.0.3 or later. See
TransactionTimeoute
(http://wiki.jboss.org/wiki/Wiki.jsp?page=TransactionTimeout)
within the JBoss wiki for more information.
6.3.9: When using gcj an java.io.CharConversionException is raised
when working with certain character sequences.
This is a known issue with gcj which raises an exception when it
reaches an unknown character or one it cannot convert. You should
add useJvmCharsetConverters=true to your connection string to
force character conversion outside of the gcj libraries, or try a
different JDK.
6.3.10: Updating a table that contains a primary key that is
either FLOAT or compound primary key that uses FLOAT fails to
update the table and raises an exception.
Connector/J adds conditions to the WHERE clause during an UPDATE
to check the old values of the primary key. If there is no match
then Connector/J considers this a failure condition and raises an
exception.
The problem is that rounding differences between supplied values
and the values stored in the database may mean that the values
never match, and hence the update fails. The issue will affect all
queries, not just those from Connector/J.
To prevent this issue, use a primary key that does not use FLOAT.
If you have to use a floating point column in your primary key use
DOUBLE or DECIMAL types in place of FLOAT.
Chapter 6. Connector/J Support
6.1. Connector/J Community Support
MySQL AB provides assistance to the user community by means of its
mailing lists. For Connector/J related issues, you can get help
from experienced users by using the MySQL and Java mailing list.
Archives and subscription information is available online at
http://lists.mysql.com/java.
For information about subscribing to MySQL mailing lists or to
browse list archives, visit http://lists.mysql.com/. See MySQL
Mailing Lists
(http://dev.mysql.com/doc/refman/5.1/en/mailing-lists.html).
Community support from experienced users is also available through
the JDBC Forum (http://forums.mysql.com/list.php?39). You may also
find help from other users in the other MySQL Forums, located at
http://forums.mysql.com. See MySQL Community Support at the MySQL
Forums (http://dev.mysql.com/doc/refman/5.1/en/forums.html).
6.2. How to Report Connector/J Bugs or Problems
The normal place to report bugs is http://bugs.mysql.com/, which
is the address for our bugs database. This database is public, and
can be browsed and searched by anyone. If you log in to the
system, you will also be able to enter new reports.
If you have found a sensitive security bug in MySQL, you can send
email to security@mysql.com.
Writing a good bug report takes patience, but doing it right the
first time saves time both for us and for yourself. A good bug
report, containing a full test case for the bug, makes it very
likely that we will fix the bug in the next release.
This section will help you write your report correctly so that you
don't waste your time doing things that may not help us much or at
all.
If you have a repeatable bug report, please report it to the bugs
database at http://bugs.mysql.com/. Any bug that we are able to
repeat has a high chance of being fixed in the next MySQL release.
To report other problems, you can use one of the MySQL mailing
lists.
Remember that it is possible for us to respond to a message
containing too much information, but not to one containing too
little. People often omit facts because they think they know the
cause of a problem and assume that some details don't matter.
A good principle is this: If you are in doubt about stating
something, state it. It is faster and less troublesome to write a
couple more lines in your report than to wait longer for the
answer if we must ask you to provide information that was missing
from the initial report.
The most common errors made in bug reports are (a) not including
the version number of Connector/J or MySQL used, and (b) not fully
describing the platform on which Connector/J is installed
(including the JVM version, and the platform type and version
number that MySQL itself is installed on).
This is highly relevant information, and in 99 cases out of 100,
the bug report is useless without it. Very often we get questions
like, "Why doesn't this work for me?" Then we find that the
feature requested wasn't implemented in that MySQL version, or
that a bug described in a report has already been fixed in newer
MySQL versions.
Sometimes the error is platform-dependent; in such cases, it is
next to impossible for us to fix anything without knowing the
operating system and the version number of the platform.
If at all possible, you should create a repeatable, stanalone
testcase that doesn't involve any third-party classes.
To streamline this process, we ship a base class for testcases
with Connector/J, named 'com.mysql.jdbc.util.BaseBugReport'. To
create a testcase for Connector/J using this class, create your
own class that inherits from com.mysql.jdbc.util.BaseBugReport and
override the methods setUp(), tearDown() and runTest().
In the setUp() method, create code that creates your tables, and
populates them with any data needed to demonstrate the bug.
In the runTest() method, create code that demonstrates the bug
using the tables and data you created in the setUp method.
In the tearDown() method, drop any tables you created in the
setUp() method.
In any of the above three methods, you should use one of the
variants of the getConnection() method to create a JDBC connection
to MySQL:
* getConnection() - Provides a connection to the JDBC URL
specified in getUrl(). If a connection already exists, that
connection is returned, otherwise a new connection is created.
* getNewConnection() - Use this if you need to get a new
connection for your bug report (i.e. there's more than one
connection involved).
* getConnection(String url) - Returns a connection using the
given URL.
* getConnection(String url, Properties props) - Returns a
connection using the given URL and properties.
If you need to use a JDBC URL that is different from
'jdbc:mysql:///test', override the method getUrl() as well.
Use the assertTrue(boolean expression) and assertTrue(String
failureMessage, boolean expression) methods to create conditions
that must be met in your testcase demonstrating the behavior you
are expecting (vs. the behavior you are observing, which is why
you are most likely filing a bug report).
Finally, create a main() method that creates a new instance of
your testcase, and calls the run method:
public static void main(String[] args) throws Exception {
new MyBugReport().run();
}
Once you have finished your testcase, and have verified that it
demonstrates the bug you are reporting, upload it with your bug
report to http://bugs.mysql.com/.
6.3. Connector/J Change History
The Connector/J Change History (Changelog) is located with the
main Changelog for MySQL. See Appendix A, "MySQL Connector/J
Change History."
Appendix A. MySQL Connector/J Change History
A.1. Changes in MySQL Connector/J 5.1.x
A.1.1. Changes in MySQL Connector/J 5.1.6 (Not yet released)
Functionality added or changed:
* Multiple result sets were not supported when using streaming
mode to return data. Both normal statements and the resul sets
from stored procedures now return multiple results sets, with
the exception of result sets using registered OUTPUT
paramaters. (Bug#33678: http://bugs.mysql.com/33678)
* XAConnections and datasources have been updated to the
JDBC-4.0 standard.
* The profiler event handling has been made extensible via the
profilerEventHandler connection property.
* Add the verifyServerCertificate propery. If set to "false" the
driver will not verify the server's certificate when useSSL is
set to "true"
When using this feature, the keystore parameters should be
specified by the clientCertificateKeyStore* properties, rather
than system properties, as the JSSE doesn't it straightforward
to have a non-verifying trust store and the "default" key
store.
Bugs fixed:
* MysqlConnectionPoolDataSource does not support
ReplicationConnection. Notice that we implemented
com.mysql.jdbc.Connection for ReplicationConnection, however,
only accessors from ConnectionProperties are implemented (not
the mutators), and they return values from the currently
active connection. All other methods from
com.mysql.jdbc.Connection are implemented, and operate on the
currently active connection, with the exception of
resetServerState() and changeUser().
(Bug#34937: http://bugs.mysql.com/34937)
* ResultSet.getTimestamp() returns incorrect values for
month/day of TIMESTAMPs when using server-side prepared
statements (not enabled by default).
(Bug#34913: http://bugs.mysql.com/34913)
* RowDataStatic does't always set the metadata in ResultSetRow,
which can lead to failures when unpacking DATE, TIME, DATETIME
and TIMESTAMP types when using absolute, relative, and
previous result set navigation methods.
(Bug#34762: http://bugs.mysql.com/34762)
* When calling isValid() on an active connection, if the timeout
is non-zero then the Connection is invalidated even if the
Connection is valid. (Bug#34703: http://bugs.mysql.com/34703)
* It was not possible to truncate a BLOB using Blog.truncate()
when using 0 as an argument.
(Bug#34677: http://bugs.mysql.com/34677)
* When using a cursor fetch for a statement, the internal
prepared statement could cause a memory leak until the
connection was closed. The internal prepared statement is now
deleted when the corresponding result set is closed.
(Bug#34518: http://bugs.mysql.com/34518)
* When retrieving the column type name of a geometry field, the
driver would return UNKNOWN instead of GEOMETRY.
(Bug#34194: http://bugs.mysql.com/34194)
* Statements with batched values do not return correct values
for getGeneratedKeys() when rewriteBatchedStatements is set to
true, and the statement has an ON DUPLICATE KEY UPDATE clause.
(Bug#34093: http://bugs.mysql.com/34093)
* The internal class ResultSetInternalMethods referenced the
non-public class com.mysql.jdbc.CachedResultSetMetaData.
(Bug#33823: http://bugs.mysql.com/33823)
* A NullPointerException could be raised when using client-side
prepared statements and enabled the prepared statement cache
using the cachePrepStmts.
(Bug#33734: http://bugs.mysql.com/33734)
* Using server side cursors and cursor fetch, the table metadata
information would return the data type name instead of the
column name. (Bug#33594: http://bugs.mysql.com/33594)
* ResultSet.getTimestamp() would throw a NullPointerException
instead of a SQLException when called on an empty ResultSet.
(Bug#33162: http://bugs.mysql.com/33162)
* Load balancing connection using best response time would
incorrectly "stick" to hosts that were down when the
connection was first created.
We solve this problem with a black list that is used during
the picking of new hosts. If the black list ends up including
all configured hosts, the driver will retry for a configurable
number of times (the retriesAllDown configuration property,
with a default of 120 times), sleeping 250ms between attempts
to pick a new connection.
We've also went ahead and made the balancing strategy
extensible. To create a new strategy, implement the interface
com.mysql.jdbc.BalanceStrategy (which also includes our
standard "extension" interface), and tell the driver to use it
by passing in the class name via the loadBalanceStrategy
configuration property.
(Bug#32877: http://bugs.mysql.com/32877)
* During a Daylight Savings Time (DST) switchover, there was no
way to store two timestamp/datetime values , as the hours end
up being the same when sent as the literal that MySQL
requires.
Note that to get this scenario to work with MySQL (since it
doesn't support per-value timezones), you need to configure
your server (or session) to be in UTC, and tell the driver not
to use the legacy date/time code by setting
useLegacyDatetimeCode to "false". This will cause the driver
to always convert to/from the server and client timezone
consistently.
This bug fix also fixes
Bug#15604: http://bugs.mysql.com/15604, by adding entirely new
date/time handling code that can be switched on by
useLegacyDatetimeCode being set to "false" as a JDBC
configuration property. For Connector/J 5.1.x, the default is
"true", in trunk and beyond it will be "false" (i.e. the old
date/time handling code will be deprecated)
(Bug#32577: http://bugs.mysql.com/32577,
Bug#15604: http://bugs.mysql.com/15604)
* When unpacking rows directly, we don't hand off error message
packets to the internal method which decodes them correctly,
so no exception is raised, and the driver than hangs trying to
read rows that aren't there. This tends to happen when calling
stored procedures, as normal SELECTs won't have an error in
this spot in the protocol unless an I/O error occurs.
(Bug#32246: http://bugs.mysql.com/32246)
* When using a connection from ConnectionPoolDataSource, some
Connection.prepareStatement() methods would return null
instead of the prepared statement.
(Bug#32101: http://bugs.mysql.com/32101)
* Using CallableStatement.setNull() on a stored function would
throw an ArrayIndexOutOfBounds exception when setting the last
parameter to null. (Bug#31823: http://bugs.mysql.com/31823)
* MysqlValidConnectionChecker doesn't properly handle
connections created using ReplicationConnection.
(Bug#31790: http://bugs.mysql.com/31790)
* Retrieving the server version information for an active
connection could return invalid information if the default
character encoding on the host was not ASCII compatible.
(Bug#31192: http://bugs.mysql.com/31192)
* Further fixes have been made to this bug in the event that a
node is non-responsive. Connector/J will now try a different
random node instead of waiting for the node to recover before
continuing. (Bug#31053: http://bugs.mysql.com/31053)
* ResultSet returned by Statement.getGeneratedKeys() is not
closed automatically when statement that created it is closed.
(Bug#30508: http://bugs.mysql.com/30508)
* DatabaseMetadata.getColumns() doesn't return the correct
column names if the connection character isn't UTF-8. A bug in
MySQL server compounded the issue, but was fixed within the
MySQL 5.0 release cycle. The fix includes changes to all the
sections of the code that access the server metadata.
(Bug#20491: http://bugs.mysql.com/20491)
* Fixed ResultSetMetadata.getColumnName() for result sets
returned from Statement.getGeneratedKeys() - it was returning
null instead of "GENERATED_KEY" as in 5.0.x.
A.1.2. Changes in MySQL Connector/J 5.1.5 (09 October 2007)
The following features are new, compared to the 5.0 series of
Connector/J
* Support for JDBC-4.0 NCHAR, NVARCHAR and NCLOB types.
* JDBC-4.0 support for setting per-connection client information
(which can be viewed in the comments section of a query via
SHOW PROCESSLIST on a MySQL server, or can be extended to
support custom persistence of the information via a public
interface).
* Support for JDBC-4.0 XML processing via JAXP interfaces to
DOM, SAX and StAX.
* JDBC-4.0 standardized unwrapping to interfaces that include
vendor extensions.
Functionality added or changed:
* Added autoSlowLog configuration property, overrides
slowQueryThreshold* properties, driver determines slow queries
by those that are slower than 5 * stddev of the mean query
time (outside the 96% percentile).
Bugs fixed:
* When a connection is in read-only mode, queries that are
wrapped in parentheses were incorrectly identified DML
statements. (Bug#28256: http://bugs.mysql.com/28256)
A.1.3. Changes in MySQL Connector/J 5.1.4 (Not Released)
Only released internally.
A.1.4. Changes in MySQL Connector/J 5.1.3 (10 September 2007)
The following features are new, compared to the 5.0 series of
Connector/J
* Support for JDBC-4.0 NCHAR, NVARCHAR and NCLOB types.
* JDBC-4.0 support for setting per-connection client information
(which can be viewed in the comments section of a query via
SHOW PROCESSLIST on a MySQL server, or can be extended to
support custom persistence of the information via a public
interface).
* Support for JDBC-4.0 XML processing via JAXP interfaces to
DOM, SAX and StAX.
* JDBC-4.0 standardized unwrapping to interfaces that include
vendor extensions.
Functionality added or changed:
* Connector/J now connects using an initial character set of
utf-8 solely for the purpose of authentication to allow user
names or database names in any character set to be used in the
JDBC connection URL. (Bug#29853: http://bugs.mysql.com/29853)
* Added two configuration parameters:
+ blobsAreStrings --- Should the driver always treat BLOBs
as Strings. Added specifically to work around dubious
metadata returned by the server for GROUP BY clauses.
Defaults to false.
+ functionsNeverReturnBlobs --- Should the driver always
treat data from functions returning BLOBs as Strings.
Added specifically to work around dubious metadata
returned by the server for GROUP BY clauses. Defaults to
false.
* Setting rewriteBatchedStatements to true now causes
CallableStatements with batched arguments to be re-written in
the form "CALL (...); CALL (...); ..." to send the batch in as
few client-server round trips as possible.
* The driver now picks appropriate internal row representation
(whole row in one buffer, or individual byte[]s for each
column value) depending on heuristics, including whether or
not the row has BLOB or TEXT types and the overall row-size.
The threshold for row size that will cause the driver to use a
buffer rather than individual byte[]s is configured by the
configuration property largeRowSizeThreshold, which has a
default value of 2KB.
* The data (and how it's stored) for ResultSet rows are now
behind an interface which allows us (in some cases) to
allocate less memory per row, in that for "streaming" result
sets, we re-use the packet used to read rows, since only one
row at a time is ever active.
* Added experimental support for statement "interceptors" via
the com.mysql.jdbc.StatementInterceptor interface, examples
are in com/mysql/jdbc/interceptors. Implement this interface
to be placed "in between" query execution, so that it can be
influenced (currently experimental).
* The driver will automatically adjust the server session
variable net_write_timeout when it determines its been asked
for a "streaming" result, and resets it to the previous value
when the result set has been consumed. (The configuration
property is named netTimeoutForStreamingResults, with a unit
of seconds, the value '0' means the driver will not try and
adjust this value).
* JDBC-4.0 ease-of-development features including
auto-registration with the DriverManager via the service
provider mechanism, standardized Connection validity checks
and categorized SQLExceptions based on
recoverability/retry-ability and class of the underlying
error.
* Statement.setQueryTimeout()s now affect the entire batch for
batched statements, rather than the individual statements that
make up the batch.
* Errors encountered during
Statement/PreparedStatement/CallableStatement.executeBatch()
when rewriteBatchStatements has been set to true now return
BatchUpdateExceptions according to the setting of
continueBatchOnError.
If continueBatchOnError is set to true, the update counts for
the "chunk" that were sent as one unit will all be set to
EXECUTE_FAILED, but the driver will attempt to process the
remainder of the batch. You can determine which "chunk" failed
by looking at the update counts returned in the
BatchUpdateException.
If continueBatchOnError is set to "false", the update counts
returned will contain all updates up-to and including the
failed "chunk", with all counts for the failed "chunk" set to
EXECUTE_FAILED.
Since MySQL doesn't return multiple error codes for
multiple-statements, or for multi-value INSERT/REPLACE, it is
the application's responsibility to handle determining which
item(s) in the "chunk" actually failed.
* New methods on com.mysql.jdbc.Statement:
setLocalInfileInputStream() and getLocalInfileInputStream():
+ setLocalInfileInputStream() sets an InputStream instance
that will be used to send data to the MySQL server for a
LOAD DATA LOCAL INFILE statement rather than a
FileInputStream or URLInputStream that represents the
path given as an argument to the statement.
This stream will be read to completion upon execution of
a LOAD DATA LOCAL INFILE statement, and will
automatically be closed by the driver, so it needs to be
reset before each call to execute*() that would cause the
MySQL server to request data to fulfill the request for
LOAD DATA LOCAL INFILE.
If this value is set to NULL, the driver will revert to
using a FileInputStream or URLInputStream as required.
+ getLocalInfileInputStream() returns the InputStream
instance that will be used to send data in response to a
LOAD DATA LOCAL INFILE statement.
This method returns NULL if no such stream has been set
via setLocalInfileInputStream().
* Setting useBlobToStoreUTF8OutsideBMP to true tells the driver
to treat [MEDIUM/LONG]BLOB columns as [LONG]VARCHAR columns
holding text encoded in UTF-8 that has characters outside the
BMP (4-byte encodings), which MySQL server can't handle
natively.
Set utf8OutsideBmpExcludedColumnNamePattern to a regex so that
column names matching the given regex will still be treated as
BLOBs The regex must follow the patterns used for the
java.util.regexpackage. The default is to exclude no columns,
and include all columns.
Set utf8OutsideBmpIncludedColumnNamePattern to specify
exclusion rules to utf8OutsideBmpExcludedColumnNamePattern".
The regex must follow the patterns used for the
java.util.regex package.
Bugs fixed:
* setObject(int, Object, int, int) delegate in
PreparedStatmentWrapper delegates to wrong method.
(Bug#30892: http://bugs.mysql.com/30892)
* NPE with null column values when padCharsWithSpace is set to
true. (Bug#30851: http://bugs.mysql.com/30851)
* Collation on VARBINARY column types would be misidentified. A
fix has been added, but this fix only works for MySQL server
versions 5.0.25 and newer, since earlier versions didn't
consistently return correct metadata for functions, and thus
results from subqueries and functions were indistinguishable
from each other, leading to type-related bugs.
(Bug#30664: http://bugs.mysql.com/30664)
* An ArithmeticException or NullPointerException would be raised
when the batch had zero members and
rewriteBatchedStatements=true when addBatch() was never
called, or executeBatch() was called immediately after
clearBatch(). (Bug#30550: http://bugs.mysql.com/30550)
* Closing a load-balanced connection would cause a
ClassCastException. (Bug#29852: http://bugs.mysql.com/29852)
* Connection checker for JBoss didn't use same method parameters
via reflection, causing connections to always seem "bad".
(Bug#29106: http://bugs.mysql.com/29106)
* DatabaseMetaData.getTypeInfo() for the types DECIMAL and
NUMERIC will return a precision of 254 for server versions
older than 5.0.3, 64 for versions 5.0.3-5.0.5 and 65 for
versions newer than 5.0.5.
(Bug#28972: http://bugs.mysql.com/28972)
* CallableStatement.executeBatch() doesn't work when connection
property noAccessToProcedureBodies has been set to true.
The fix involves changing the behavior of
noAccessToProcedureBodies,in that the driver will now report
all paramters as "IN" paramters but allow callers to call
registerOutParameter() on them without throwing an exception.
(Bug#28689: http://bugs.mysql.com/28689)
* DatabaseMetaData.getColumns() doesn't contain SCOPE_* or
IS_AUTOINCREMENT columns.
(Bug#27915: http://bugs.mysql.com/27915)
* Schema objects with identifiers other than the connection
character aren't retrieved correctly in ResultSetMetadata.
(Bug#27867: http://bugs.mysql.com/27867)
* Connection.getServerCharacterEncoding() doesn't work for
servers with version >= 4.1.
(Bug#27182: http://bugs.mysql.com/27182)
* The automated SVN revisions in DBMD.getDriverVersion(). The
SVN revision of the directory is now inserted into the version
information during the build.
(Bug#21116: http://bugs.mysql.com/21116)
* Specifying a "validation query" in your connection pool that
starts with "/* ping */" _exactly_ will cause the driver to
instead send a ping to the server and return a fake result set
(much lighter weight), and when using a ReplicationConnection
or a LoadBalancedConnection, will send the ping across all
active connections.
A.1.5. Changes in MySQL Connector/J 5.1.2 (29 June 2007)
This is a new Beta development release, fixing recently discovered
bugs.
Functionality added or changed:
* Setting the configuration property rewriteBatchedStatements to
true will now cause the driver to rewrite batched prepared
statements with more than 3 parameter sets in a batch into
multi-statements (separated by ";") if they are not plain
(that is, without SELECT or ON DUPLICATE KEY UPDATE clauses)
INSERT or REPLACE statements.
A.1.6. Changes in MySQL Connector/J 5.1.1 (22 June 2007)
This is a new Alpha development release, adding new features and
fixing recently discovered bugs.
Functionality added or changed:
* Incompatible Change: Pulled vendor-extension methods of
Connection implementation out into an interface to support
java.sql.Wrapper functionality from ConnectionPoolDataSource.
The vendor extensions are javadoc'd in the
com.mysql.jdbc.Connection interface.
For those looking further into the driver implementation, it
is not an API that is used for plugability of implementations
inside our driver (which is why there are still references to
ConnectionImpl throughout the code).
We've also added server and client prepareStatement() methods
that cover all of the variants in the JDBC API.
Connection.serverPrepare(String) has been re-named to
Connection.serverPrepareStatement() for consistency with
Connection.clientPrepareStatement().
* Row navigation now causes any streams/readers open on the
result set to be closed, as in some cases we're reading
directly from a shared network packet and it will be
overwritten by the "next" row.
* Made it possible to retrieve prepared statement parameter
bindings (to be used in StatementInterceptors, primarily).
* Externalized the descriptions of connection properties.
* The data (and how it's stored) for ResultSet rows are now
behind an interface which allows us (in some cases) to
allocate less memory per row, in that for "streaming" result
sets, we re-use the packet used to read rows, since only one
row at a time is ever active.
* Similar to Connection, we pulled out vendor extensions to
Statement into an interface named com.mysql.Statement, and
moved the Statement class into com.mysql.StatementImpl. The
two methods (javadoc'd in com.mysql.Statement are
enableStreamingResults(), which already existed, and
disableStreamingResults() which sets the statement instance
back to the fetch size and result set type it had before
enableStreamingResults() was called.
* Driver now picks appropriate internal row representation
(whole row in one buffer, or individual byte[]s for each
column value) depending on heuristics, including whether or
not the row has BLOB or TEXT types and the overall row-size.
The threshold for row size that will cause the driver to use a
buffer rather than individual byte[]s is configured by the
configuration property largeRowSizeThreshold, which has a
default value of 2KB.
* Added experimental support for statement "interceptors" via
the com.mysql.jdbc.StatementInterceptor interface, examples
are in com/mysql/jdbc/interceptors.
Implement this interface to be placed "in between" query
execution, so that you can influence it. (currently
experimental).
StatementInterceptors are "chainable" when configured by the
user, the results returned by the "current" interceptor will
be passed on to the next on in the chain, from left-to-right
order, as specified by the user in the JDBC configuration
property statementInterceptors.
* See the sources (fully javadoc'd) for
com.mysql.jdbc.StatementInterceptor for more details until we
iron out the API and get it documented in the manual.
* Setting rewriteBatchedStatements to true now causes
CallableStatements with batched arguments to be re-written in
the form CALL (...); CALL (...); ... to send the batch in as
few client-server round trips as possible.
A.1.7. Changes in MySQL Connector/J 5.1.0 (11 April 2007)
This is the first public alpha release of the current Connector/J
5.1 development branch, providing an insight to upcoming features.
Although some of these are still under development, this release
includes the following new features and changes (in comparison to
the current Connector/J 5.0 production release):
Important change: Due to a number of issues with the use of
server-side prepared statements, Connector/J 5.0.5 has disabled
their use by default. The disabling of server-side prepared
statements does not affect the operation of the connector in any
way.
To enable server-side prepared statements you must add the
following configuration property to your connector string:
useServerPrepStmts=true
The default value of this property is false (that is, Connector/J
does not use server-side prepared statements).
Note
The disabling of server-side prepared statements does not affect
the operation of the connector. However, if you use the
useTimezone=true connection option and use client-side prepared
statements (instead of server-side prepared statements) you should
also set useSSPSCompatibleTimezoneShift=true.
Functionality added or changed:
* Refactored CommunicationsException into a JDBC-3.0 version,
and a JDBC-4.0 version (which extends SQLRecoverableException,
now that it exists).
Note
This change means that if you were catching
com.mysql.jdbc.CommunicationsException in your applications
instead of looking at the SQLState class of 08, and are moving
to Java 6 (or newer), you need to change your imports to that
exception to be
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException, as
the old class will not be instantiated for communications
link-related errors under Java 6.
* Added support for JDBC-4.0 categorized SQLExceptions.
* Added support for JDBC-4.0's NCLOB, and NCHAR/NVARCHAR types.
* com.mysql.jdbc.java6.javac --- full path to your Java-6 javac
executable
* Added support for JDBC-4.0's SQLXML interfaces.
* Re-worked Ant buildfile to build JDBC-4.0 classes separately,
as well as support building under Eclipse (since Eclipse can't
mix/match JDKs).
To build, you must set JAVA_HOME to J2SDK-1.4.2 or Java-5, and
set the following properties on your Ant command line:
+ com.mysql.jdbc.java6.javac --- full path to your Java-6
javac executable
+ com.mysql.jdbc.java6.rtjar --- full path to your Java-6
rt.jar file
* New feature --- driver will automatically adjust session
variable net_write_timeout when it determines it has been
asked for a "streaming" result, and resets it to the previous
value when the result set has been consumed. (configuration
property is named netTimeoutForStreamingResults value and has
a unit of seconds, the value 0 means the driver will not try
and adjust this value).
* Added support for JDBC-4.0's client information. The backend
storage of information provided via Connection.setClientInfo()
and retrieved by Connection.getClientInfo() is pluggable by
any class that implements the
com.mysql.jdbc.JDBC4ClientInfoProvider interface and has a
no-args constructor.
The implementation used by the driver is configured using the
clientInfoProvider configuration property (with a default of
value of com.mysql.jdbc.JDBC4CommentClientInfoProvider, an
implementation which lists the client information as a comment
prepended to every query sent to the server).
This functionality is only available when using Java-6 or
newer.
* com.mysql.jdbc.java6.rtjar --- full path to your Java-6 rt.jar
file
* Added support for JDBC-4.0's Wrapper interface.
A.2. Changes in MySQL Connector/J 5.0.x
A.2.1. Changes in MySQL Connector/J 5.0.8 (09 October 2007)
Functionality added or changed:
* blobsAreStrings --- Should the driver always treat BLOBs as
Strings. Added specifically to work around dubious metadata
returned by the server for GROUP BY clauses. Defaults to
false.
* Added two configuration parameters:
+ blobsAreStrings --- Should the driver always treat BLOBs
as Strings. Added specifically to work around dubious
metadata returned by the server for GROUP BY clauses.
Defaults to false.
+ functionsNeverReturnBlobs --- Should the driver always
treat data from functions returning BLOBs as Strings.
Added specifically to work around dubious metadata
returned by the server for GROUP BY clauses. Defaults to
false.
* functionsNeverReturnBlobs --- Should the driver always treat
data from functions returning BLOBs as Strings. Added
specifically to work around dubious metadata returned by the
server for GROUP BY clauses. Defaults to false.
* XAConnections now start in auto-commit mode (as per JDBC-4.0
specification clarification).
* Driver will now fall back to sane defaults for
max_allowed_packet and net_buffer_length if the server reports
them incorrectly (and will log this situation at WARN level,
since it's actually an error condition).
Bugs fixed:
* Connections established using URLs of the form
jdbc:mysql:loadbalance:// weren't doing failover if they tried
to connect to a MySQL server that was down. The driver now
attempts connections to the next "best" (depending on the load
balance strategy in use) server, and continues to attempt
connecting to the next "best" server every 250 milliseconds
until one is found that is up and running or 5 minutes has
passed.
If the driver gives up, it will throw the last-received
SQLException. (Bug#31053: http://bugs.mysql.com/31053)
* setObject(int, Object, int, int) delegate in
PreparedStatmentWrapper delegates to wrong method.
(Bug#30892: http://bugs.mysql.com/30892)
* NPE with null column values when padCharsWithSpace is set to
true. (Bug#30851: http://bugs.mysql.com/30851)
* Collation on VARBINARY column types would be misidentified. A
fix has been added, but this fix only works for MySQL server
versions 5.0.25 and newer, since earlier versions didn't
consistently return correct metadata for functions, and thus
results from subqueries and functions were indistinguishable
from each other, leading to type-related bugs.
(Bug#30664: http://bugs.mysql.com/30664)
* An ArithmeticException or NullPointerException would be raised
when the batch had zero members and
rewriteBatchedStatements=true when addBatch() was never
called, or executeBatch() was called immediately after
clearBatch(). (Bug#30550: http://bugs.mysql.com/30550)
* Closing a load-balanced connection would cause a
ClassCastException. (Bug#29852: http://bugs.mysql.com/29852)
* Connection checker for JBoss didn't use same method parameters
via reflection, causing connections to always seem "bad".
(Bug#29106: http://bugs.mysql.com/29106)
* DatabaseMetaData.getTypeInfo() for the types DECIMAL and
NUMERIC will return a precision of 254 for server versions
older than 5.0.3, 64 for versions 5.0.3-5.0.5 and 65 for
versions newer than 5.0.5.
(Bug#28972: http://bugs.mysql.com/28972)
* CallableStatement.executeBatch() doesn't work when connection
property noAccessToProcedureBodies has been set to true.
The fix involves changing the behavior of
noAccessToProcedureBodies,in that the driver will now report
all paramters as "IN" paramters but allow callers to call
registerOutParameter() on them without throwing an exception.
(Bug#28689: http://bugs.mysql.com/28689)
* When a connection is in read-only mode, queries that are
wrapped in parentheses were incorrectly identified DML
statements. (Bug#28256: http://bugs.mysql.com/28256)
* UNSIGNED types not reported via DBMD.getTypeInfo(), and
capitalization of type names is not consistent between
DBMD.getColumns(), RSMD.getColumnTypeName() and
DBMD.getTypeInfo().
This fix also ensures that the precision of UNSIGNED MEDIUMINT
and UNSIGNED BIGINT is reported correctly via
DBMD.getColumns(). (Bug#27916: http://bugs.mysql.com/27916)
* DatabaseMetaData.getColumns() doesn't contain SCOPE_* or
IS_AUTOINCREMENT columns.
(Bug#27915: http://bugs.mysql.com/27915)
* Schema objects with identifiers other than the connection
character aren't retrieved correctly in ResultSetMetadata.
(Bug#27867: http://bugs.mysql.com/27867)
* Cached metadata with PreparedStatement.execute() throws
NullPointerException. (Bug#27412: http://bugs.mysql.com/27412)
* Connection.getServerCharacterEncoding() doesn't work for
servers with version >= 4.1.
(Bug#27182: http://bugs.mysql.com/27182)
* The automated SVN revisions in DBMD.getDriverVersion(). The
SVN revision of the directory is now inserted into the version
information during the build.
(Bug#21116: http://bugs.mysql.com/21116)
* Specifying a "validation query" in your connection pool that
starts with "/* ping */" _exactly_ will cause the driver to
instead send a ping to the server and return a fake result set
(much lighter weight), and when using a ReplicationConnection
or a LoadBalancedConnection, will send the ping across all
active connections.
A.2.2. Changes in MySQL Connector/J 5.0.7 (20 July 2007)
Functionality added or changed:
* The driver will now automatically set useServerPrepStmts to
true when useCursorFetch has been set to true, since the
feature requires server-side prepared statements in order to
function.
* tcpKeepAlive - Should the driver set SO_KEEPALIVE (default
true)?
* Give more information in EOFExceptions thrown out of MysqlIO
(how many bytes the driver expected to read, how many it
actually read, say that communications with the server were
unexpectedly lost).
* Driver detects when it is running in a ColdFusion MX server
(tested with version 7), and uses the configuration bundle
coldFusion, which sets useDynamicCharsetInfo to false (see
previous entry), and sets useLocalSessionState and
autoReconnect to true.
* tcpNoDelay - Should the driver set SO_TCP_NODELAY (disabling
the Nagle Algorithm, default true)?
* Added configuration property slowQueryThresholdNanos - if
useNanosForElapsedTime is set to true, and this property is
set to a non-zero value the driver will use this threshold (in
nanosecond units) to determine if a query was slow, instead of
using millisecond units.
* tcpRcvBuf - Should the driver set SO_RCV_BUF to the given
value? The default value of '0', means use the platform
default value for this property.
* Setting useDynamicCharsetInfo to false now causes driver to
use static lookups for collations as well (makes
ResultSetMetadata.isCaseSensitive() much more efficient, which
leads to performance increase for ColdFusion, which calls this
method for every column on every table it sees, it appears).
* Added configuration properties to allow tuning of TCP/IP
socket parameters:
+ tcpNoDelay - Should the driver set SO_TCP_NODELAY
(disabling the Nagle Algorithm, default true)?
+ tcpKeepAlive - Should the driver set SO_KEEPALIVE
(default true)?
+ tcpRcvBuf - Should the driver set SO_RCV_BUF to the given
value? The default value of '0', means use the platform
default value for this property.
+ tcpSndBuf - Should the driver set SO_SND_BUF to the given
value? The default value of '0', means use the platform
default value for this property.
+ tcpTrafficClass - Should the driver set traffic class or
type-of-service fields? See the documentation for
java.net.Socket.setTrafficClass() for more information.
* Setting the configuration parameter useCursorFetch to true for
MySQL-5.0+ enables the use of cursors that allow Connector/J
to save memory by fetching result set rows in chunks (where
the chunk size is set by calling setFetchSize() on a Statement
or ResultSet) by using fully-materialized cursors on the
server.
* tcpSndBuf - Should the driver set SO_SND_BUF to the given
value? The default value of '0', means use the platform
default value for this property.
* tcpTrafficClass - Should the driver set traffic class or
type-of-service fields? See the documentation for
java.net.Socket.setTrafficClass() for more information.
* Added new debugging functionality - Setting configuration
property includeInnodbStatusInDeadlockExceptions to true will
cause the driver to append the output of SHOW ENGINE INNODB
STATUS to deadlock-related exceptions, which will enumerate
the current locks held inside InnoDB.
* Added configuration property useNanosForElapsedTime - for
profiling/debugging functionality that measures elapsed time,
should the driver try to use nanoseconds resolution if
available (requires JDK >= 1.5)?
Note
If useNanosForElapsedTime is set to true, and this property is
set to "0" (or left default), then elapsed times will still be
measured in nanoseconds (if possible), but the slow query
threshold will be converted from milliseconds to nanoseconds,
and thus have an upper bound of approximately 2000
milliseconds (as that threshold is represented as an integer,
not a long).
Bugs fixed:
* Don't send any file data in response to LOAD DATA LOCAL INFILE
if the feature is disabled at the client side. This is to
prevent a malicious server or man-in-the-middle from asking
the client for data that the client is not expecting. Thanks
to Jan Kneschke for discovering the exploit and Andrey
"Poohie" Hristov, Konstantin Osipov and Sergei Golubchik for
discussions about implications and possible fixes.
(Bug#29605: http://bugs.mysql.com/29605)
* Parser in client-side prepared statements runs to end of
statement, rather than end-of-line for '#' comments. Also
added support for '--' single-line comments.
(Bug#28956: http://bugs.mysql.com/28956)
* Parser in client-side prepared statements eats character
following '/' if it's not a multi-line comment.
(Bug#28851: http://bugs.mysql.com/28851)
* PreparedStatement.getMetaData() for statements containing
leading one-line comments is not returned correctly.
As part of this fix, we also overhauled detection of DML for
executeQuery() and SELECTs for executeUpdate() in plain and
prepared statements to be aware of the same types of comments.
(Bug#28469: http://bugs.mysql.com/28469)
A.2.3. Changes in MySQL Connector/J 5.0.6 (15 May 2007)
Functionality added or changed:
* Added an experimental load-balanced connection designed for
use with SQL nodes in a MySQL Cluster/NDB environment (This is
not for master-slave replication. For that, we suggest you
look at ReplicationConnection or lbpool).
If the JDBC URL starts with
jdbc:mysql:loadbalance://host-1,host-2,...host-n, the driver
will create an implementation of java.sql.Connection that load
balances requests across a series of MySQL JDBC connections to
the given hosts, where the balancing takes place after
transaction commit.
Therefore, for this to work (at all), you must use
transactions, even if only reading data.
Physical connections to the given hosts will not be created
until needed.
The driver will invalidate connections that it detects have
had communication errors when processing a request. A new
connection to the problematic host will be attempted the next
time it is selected by the load balancing algorithm.
There are two choices for load balancing algorithms, which may
be specified by the loadBalanceStrategy JDBC URL configuration
property:
+ random --- the driver will pick a random host for each
request. This tends to work better than round-robin, as
the randomness will somewhat account for spreading loads
where requests vary in response time, while round-robin
can sometimes lead to overloaded nodes if there are
variations in response times across the workload.
+ bestResponseTime --- the driver will route the request to
the host that had the best response time for the previous
transaction.
* bestResponseTime --- the driver will route the request to the
host that had the best response time for the previous
transaction.
* Added configuration property padCharsWithSpace (defaults to
false). If set to true, and a result set column has the CHAR
type and the value does not fill the amount of characters
specified in the DDL for the column, the driver will pad the
remaining characters with space (for ANSI compliance).
* When useLocalSessionState is set to true and connected to a
MySQL-5.0 or later server, the JDBC driver will now determine
whether an actual commit or rollback statement needs to be
sent to the database when Connection.commit() or
Connection.rollback() is called.
This is especially helpful for high-load situations with
connection pools that always call Connection.rollback() on
connection check-in/check-out because it avoids a round-trip
to the server.
* Added configuration property useDynamicCharsetInfo. If set to
false (the default), the driver will use a per-connection
cache of character set information queried from the server
when necessary, or when set to true, use a built-in static
mapping that is more efficient, but isn't aware of custom
character sets or character sets implemented after the release
of the JDBC driver.
Note
This only affects the padCharsWithSpace configuration property
and the ResultSetMetaData.getColumnDisplayWidth() method.
* New configuration property, enableQueryTimeouts (default
true).
When enabled, query timeouts set via
Statement.setQueryTimeout() use a shared java.util.Timer
instance for scheduling. Even if the timeout doesn't expire
before the query is processed, there will be memory used by
the TimerTask for the given timeout which won't be reclaimed
until the time the timeout would have expired if it hadn't
been cancelled by the driver. High-load environments might
want to consider disabling this functionality. (this
configuration property is part of the maxPerformance
configuration bundle).
* Give better error message when "streaming" result sets, and
the connection gets clobbered because of exceeding
net_write_timeout on the server.
* random --- the driver will pick a random host for each
request. This tends to work better than round-robin, as the
randomness will somewhat account for spreading loads where
requests vary in response time, while round-robin can
sometimes lead to overloaded nodes if there are variations in
response times across the workload.
* com.mysql.jdbc.[NonRegistering]Driver now understands URLs of
the format jdbc:mysql:replication:// and
jdbc:mysql:loadbalance:// which will create a
ReplicationConnection (exactly like when using
[NonRegistering]ReplicationDriver) and an experimental
load-balanced connection designed for use with SQL nodes in a
MySQL Cluster/NDB environment, respectively.
In an effort to simplify things, we're working on deprecating
multiple drivers, and instead specifying different core
behavior based upon JDBC URL prefixes, so watch for
[NonRegistering]ReplicationDriver to eventually disappear, to
be replaced with com.mysql.jdbc[NonRegistering]Driver with the
new URL prefix.
* Fixed issue where a failed-over connection would let an
application call setReadOnly(false), when that call should be
ignored until the connection is reconnected to a writable
master unless failoverReadOnly had been set to false.
* Driver will now use INSERT INTO ... VALUES (DEFAULT)form of
statement for updatable result sets for ResultSet.insertRow(),
rather than pre-populating the insert row with values from
DatabaseMetaData.getColumns()(which results in a SHOW FULL
COLUMNS on the server for every result set). If an application
requires access to the default values before insertRow() has
been called, the JDBC URL should be configured with
populateInsertRowWithDefaultValues set to true.
This fix specifically targets performance issues with
ColdFusion and the fact that it seems to ask for updatable
result sets no matter what the application does with them.
* More intelligent initial packet sizes for the "shared" packets
are used (512 bytes, rather than 16K), and initial packets
used during handshake are now sized appropriately as to not
require reallocation.
Bugs fixed:
* More useful error messages are generated when the driver
thinks a result set is not updatable. (Thanks to Ashley
Martens for the patch).
(Bug#28085: http://bugs.mysql.com/28085)
* Connection.getTransactionIsolation() uses "SHOW VARIABLES
LIKE" which is very inefficient on MySQL-5.0+ servers.
(Bug#27655: http://bugs.mysql.com/27655)
* Fixed issue where calling getGeneratedKeys() on a prepared
statement after calling execute() didn't always return the
generated keys (executeUpdate() worked fine however).
(Bug#27655: http://bugs.mysql.com/27655)
* CALL /* ... */ some_proc() doesn't work. As a side effect of
this fix, you can now use /* */ and # comments when preparing
statements using client-side prepared statement emulation.
If the comments happen to contain parameter markers (?), they
will be treated as belonging to the comment (that is, not
recognized) rather than being a parameter of the statement.
Note
The statement when sent to the server will contain the
comments as-is, they're not stripped during the process of
preparing the PreparedStatement or CallableStatement.
(Bug#27400: http://bugs.mysql.com/27400)
* ResultSet.get*() with a column index < 1 returns misleading
error message. (Bug#27317: http://bugs.mysql.com/27317)
* Using ResultSet.get*() with a column index less than 1 returns
a misleading error message.
(Bug#27317: http://bugs.mysql.com/27317)
* Comments in DDL of stored procedures/functions confuse
procedure parser, and thus metadata about them can not be
created, leading to inability to retrieve said metadata, or
execute procedures that have certain comments in them.
(Bug#26959: http://bugs.mysql.com/26959)
* Fast date/time parsing doesn't take into account 00:00:00 as a
legal value. (Bug#26789: http://bugs.mysql.com/26789)
* PreparedStatement is not closed in BlobFromLocator.getBytes().
(Bug#26592: http://bugs.mysql.com/26592)
* When the configuration property useCursorFetch was set to
true, sometimes server would return new, more exact metadata
during the execution of the server-side prepared statement
that enables this functionality, which the driver ignored
(using the original metadata returned during prepare()),
causing corrupt reading of data due to type mismatch when the
actual rows were returned.
(Bug#26173: http://bugs.mysql.com/26173)
* CallableStatements with OUT/INOUT parameters that are "binary"
(BLOB, BIT, (VAR)BINARY, JAVA_OBJECT) have extra 7 bytes.
(Bug#25715: http://bugs.mysql.com/25715)
* Whitespace surrounding storage/size specifiers in stored
procedure parameters declaration causes NumberFormatException
to be thrown when calling stored procedure on JDK-1.5 or
newer, as the Number classes in JDK-1.5+ are whitespace
intolerant. (Bug#25624: http://bugs.mysql.com/25624)
* Client options not sent correctly when using SSL, leading to
stored procedures not being able to return results. Thanks to
Don Cohen for the bug report, testcase and patch.
(Bug#25545: http://bugs.mysql.com/25545)
* Statement.setMaxRows() is not effective on result sets
materialized from cursors.
(Bug#25517: http://bugs.mysql.com/25517)
* BIT(> 1) is returned as java.lang.String from
ResultSet.getObject() rather than byte[].
(Bug#25328: http://bugs.mysql.com/25328)
A.2.4. Changes in MySQL Connector/J 5.0.5 (02 March 2007)
Functionality added or changed:
* Usage Advisor will now issue warnings for result sets with
large numbers of rows. You can configure the trigger value by
using the resultSetSizeThreshold parameter, which has a
default value of 100.
* The rewriteBatchedStatements feature can now be used with
server-side prepared statements.
* Important change: Due to a number of issues with the use of
server-side prepared statements, Connector/J 5.0.5 has
disabled their use by default. The disabling of server-side
prepared statements does not affect the operation of the
connector in any way.
To enable server-side prepared statements you must add the
following configuration property to your connector string:
useServerPrepStmts=true
The default value of this property is false (that is,
Connector/J does not use server-side prepared statements).
* Improved speed of datetime parsing for ResultSets that come
from plain or non-server-side prepared statements. You can
enable old implementation with useFastDateParsing=false as a
configuration parameter.
* Usage Advisor now detects empty results sets and does not
report on columns not referenced in those empty sets.
* Fixed logging of XA commands sent to server, it's now
configurable via logXaCommands property (defaults to false).
* Added configuration property localSocketAddress,which is the
hostname or IP address given to explicitly configure the
interface that the driver will bind the client side of the
TCP/IP connection to when connecting.
* We've added a new configuration option
treatUtilDateAsTimestamp, which is false by default, as (1) We
already had specific behavior to treat java.util.Date as a
java.sql.Timestamp because it's useful to many folks, and (2)
that behavior will very likely be required for drivers
JDBC-post-4.0.
Bugs fixed:
* Connection property socketFactory wasn't exposed via correctly
named mutator/accessor, causing data source implementations
that use JavaBean naming conventions to set properties to fail
to set the property (and in the case of SJAS, fail silently
when trying to set this parameter).
(Bug#26326: http://bugs.mysql.com/26326)
* A query execution which timed out did not always throw a
MySQLTimeoutException.
(Bug#25836: http://bugs.mysql.com/25836)
* Storing a java.util.Date object in a BLOB column would not be
serialized correctly during setObject.
(Bug#25787: http://bugs.mysql.com/25787)
* Timer instance used for Statement.setQueryTimeout() created
per-connection, rather than per-VM, causing memory leak.
(Bug#25514: http://bugs.mysql.com/25514)
* EscapeProcessor gets confused by multiple backslashes. We now
push the responsibility of syntax errors back on to the server
for most escape sequences.
(Bug#25399: http://bugs.mysql.com/25399)
* INOUT parameters in CallableStatements get doubly-escaped.
(Bug#25379: http://bugs.mysql.com/25379)
* When using the rewriteBatchedStatements connection option with
PreparedState.executeBatch() an internal memory leak would
occur. (Bug#25073: http://bugs.mysql.com/25073)
* Fixed issue where field-level for metadata from
DatabaseMetaData when using INFORMATION_SCHEMA didn't have
references to current connections, sometimes leading to Null
Pointer Exceptions (NPEs) when introspecting them via
ResultSetMetaData. (Bug#25073: http://bugs.mysql.com/25073)
* StringUtils.indexOfIgnoreCaseRespectQuotes() isn't
case-insensitive on the first character of the target. This
bug also affected rewriteBatchedStatements functionality when
prepared statements did not use uppercase for the VALUES
clause. (Bug#25047: http://bugs.mysql.com/25047)
* Client-side prepared statement parser gets confused by in-line
comments /*...*/ and therefore cannot rewrite batch statements
or reliably detect the type of statements when they are used.
(Bug#25025: http://bugs.mysql.com/25025)
* Results sets from UPDATE statements that are part of
multi-statement queries would cause an SQLException error,
"Result is from UPDATE".
(Bug#25009: http://bugs.mysql.com/25009)
* Specifying US-ASCII as the character set in a connection to a
MySQL 4.1 or newer server does not map correctly.
(Bug#24840: http://bugs.mysql.com/24840)
* Using DatabaseMetaData.getSQLKeywords() does not return a all
of the of the reserved keywords for the current MySQL version.
Current implementation returns the list of reserved words for
MySQL 5.1, and does not distinguish between versions.
(Bug#24794: http://bugs.mysql.com/24794)
* Calling Statement.cancel() could result in a Null Pointer
Exception (NPE). (Bug#24721: http://bugs.mysql.com/24721)
* Using setFetchSize() breaks prepared SHOW and other commands.
(Bug#24360: http://bugs.mysql.com/24360)
* Calendars and timezones are now lazily instantiated when
required. (Bug#24351: http://bugs.mysql.com/24351)
* Using DATETIME columns would result in time shifts when
useServerPrepStmts was true. The reason was due to different
behavior when using client-side compared to server-side
prepared statements and the useJDBCCompliantTimezoneShift
option. This is now fixed if moving from server-side prepared
statements to client-side prepared statements by setting
useSSPSCompatibleTimezoneShift to true, as the driver can't
tell if this is a new deployment that never used server-side
prepared statements, or if it is an existing deployment that
is switching to client-side prepared statements from
server-side prepared statements.
(Bug#24344: http://bugs.mysql.com/24344)
* Connector/J now returns a better error message when server
doesn't return enough information to determine stored
procedure/function parameter types.
(Bug#24065: http://bugs.mysql.com/24065)
* A connection error would occur when connecting to a MySQL
server with certain character sets. Some collations/character
sets reported as "unknown" (specifically cias variants of
existing character sets), and inability to override the
detected server character set.
(Bug#23645: http://bugs.mysql.com/23645)
* Inconsistency between getSchemas and INFORMATION_SCHEMA.
(Bug#23304: http://bugs.mysql.com/23304)
* DatabaseMetaData.getSchemas() doesn't return a TABLE_CATALOG
column. (Bug#23303: http://bugs.mysql.com/23303)
* When using a JDBC connection URL that is malformed, the
NonRegisteringDriver.getPropertyInfo method will throw a Null
Pointer Exception (NPE).
(Bug#22628: http://bugs.mysql.com/22628)
* Some exceptions thrown out of StandardSocketFactory were
needlessly wrapped, obscuring their true cause, especially
when using socket timeouts.
(Bug#21480: http://bugs.mysql.com/21480)
* When using a server-side prepared statement the driver would
send timestamps to the server using nanoseconds instead of
milliseconds. (Bug#21438: http://bugs.mysql.com/21438)
* When using server-side prepared statements and timestamp
columns, value would be incorrectly populated (with
nanoseconds, not microseconds).
(Bug#21438: http://bugs.mysql.com/21438)
* ParameterMetaData throws NullPointerException when prepared
SQL has a syntax error. Added generateSimpleParameterMetadata
configuration property, which when set to true will generate
metadata reflecting VARCHAR for every parameter (the default
is false, which will cause an exception to be thrown if no
parameter metadata for the statement is actually available).
(Bug#21267: http://bugs.mysql.com/21267)
* Fixed an issue where XADataSources couldn't be bound into
JNDI, as the DataSourceFactory didn't know how to create
instances of them.
Other changes:
* Avoid static synchronized code in JVM class libraries for
dealing with default timezones.
* Performance enhancement of initial character set
configuration, driver will only send commands required to
configure connection character set session variables if the
current values on the server do not match what is required.
* Re-worked stored procedure parameter parser to be more robust.
Driver no longer requires BEGIN in stored procedure
definition, but does have requirement that if a stored
function begins with a label directly after the "returns"
clause, that the label is not a quoted identifier.
* Throw exceptions encountered during timeout to thread calling
Statement.execute*(), rather than RuntimeException.
* Changed cached result set metadata (when using
cacheResultSetMetadata=true) to be cached per-connection
rather than per-statement as previously implemented.
* Reverted back to internal character conversion routines for
single-byte character sets, as the ones internal to the JVM
are using much more CPU time than our internal implementation.
* When extracting foreign key information from SHOW CREATE TABLE
in DatabaseMetaData, ignore exceptions relating to tables
being missing (which could happen for cross-reference or
imported-key requests, as the list of tables is generated
first, then iterated).
* Fixed some Null Pointer Exceptions (NPEs) when cached metadata
was used with UpdatableResultSets.
* Take localSocketAddress property into account when creating
instances of CommunicationsException when the underyling
exception is a java.net.BindException, so that a friendlier
error message is given with a little internal diagnostics.
* Fixed cases where ServerPreparedStatements weren't using
cached metadata when cacheResultSetMetadata=true was used.
* Use a java.util.TreeMap to map column names to ordinal indexes
for ResultSet.findColumn() instead of a HashMap. This allows
us to have case-insensitive lookups (required by the JDBC
specification) without resorting to the many transient object
instances needed to support this requirement with a normal
HashMap with either case-adjusted keys, or case-insensitive
keys. (In the worst case scenario for lookups of a 1000 column
result set, TreeMaps are about half as fast wall-clock time as
a HashMap, however in normal applications their use gives many
orders of magnitude reduction in transient object instance
creation which pays off later for CPU usage in garbage
collection).
* When using cached metadata, skip field-level metadata packets
coming from the server, rather than reading them and
discarding them without creating com.mysql.jdbc.Field
instances.
A.2.5. Changes in MySQL Connector/J 5.0.4 (20 October 2006)
Bugs fixed:
* DBMD.getColumns() does not return expected COLUMN_SIZE for the
SET type, now returns length of largest possible set
disregarding whitespace or the "," delimitters to be
consistent with the ODBC driver.
(Bug#22613: http://bugs.mysql.com/22613)
* Added new _ci collations to CharsetMapping - utf8_unicode_ci
not working. (Bug#22456: http://bugs.mysql.com/22456)
* Driver was using milliseconds for Statement.setQueryTimeout()
when specification says argument is to be in seconds.
(Bug#22359: http://bugs.mysql.com/22359)
* Workaround for server crash when calling stored procedures via
a server-side prepared statement (driver now detects
prepare(stored procedure) and substitutes client-side prepared
statement). (Bug#22297: http://bugs.mysql.com/22297)
* Driver issues truncation on write exception when it shouldn't
(due to sending big decimal incorrectly to server with
server-side prepared statement).
(Bug#22290: http://bugs.mysql.com/22290)
* Newlines causing whitespace to span confuse procedure parser
when getting parameter metadata for stored procedures.
(Bug#22024: http://bugs.mysql.com/22024)
* When using information_schema for metadata, COLUMN_SIZE for
getColumns() is not clamped to range of java.lang.Integer as
is the case when not using information_schema, thus leading to
a truncation exception that isn't present when not using
information_schema. (Bug#21544: http://bugs.mysql.com/21544)
* Column names don't match metadata in cases where server
doesn't return original column names (column functions) thus
breaking compatibility with applications that expect 1-1
mappings between findColumn() and rsmd.getColumnName(),
usually manifests itself as "Can't find column ('')"
exceptions. (Bug#21379: http://bugs.mysql.com/21379)
* Driver now sends numeric 1 or 0 for client-prepared statement
setBoolean() calls instead of '1' or '0'.
* Fixed configuration property jdbcCompliantTruncation was not
being used for reads of result set values.
* DatabaseMetaData correctly reports true for supportsCatalog*()
methods.
* Driver now supports {call sp} (without "()" if procedure has
no arguments).
A.2.6. Changes in MySQL Connector/J 5.0.3 (26 July 2006)
Functionality added or changed:
* Added configuration option noAccessToProcedureBodies which
will cause the driver to create basic parameter metadata for
CallableStatements when the user does not have access to
procedure bodies via SHOW CREATE PROCEDURE or selecting from
mysql.proc instead of throwing an exception. The default value
for this option is false
Bugs fixed:
* Fixed Statement.cancel() causes NullPointerException if
underlying connection has been closed due to server failure.
(Bug#20650: http://bugs.mysql.com/20650)
* If the connection to the server has been closed due to a
server failure, then the cleanup process will call
Statement.cancel(), triggering a NullPointerException, even
though there is no active connection.
(Bug#20650: http://bugs.mysql.com/20650)
A.2.7. Changes in MySQL Connector/J 5.0.2 (11 July 2006)
Bugs fixed:
* MysqlXaConnection.recover(int flags) now allows combinations
of XAResource.TMSTARTRSCAN and TMENDRSCAN. To simulate the
"scanning" nature of the interface, we return all prepared
XIDs for TMSTARTRSCAN, and no new XIDs for calls with
TMNOFLAGS, or TMENDRSCAN when not in combination with
TMSTARTRSCAN. This change was made for API compliance, as well
as integration with IBM WebSphere's transaction manager.
(Bug#20242: http://bugs.mysql.com/20242)
* Fixed MysqlValidConnectionChecker for JBoss doesn't work with
MySQLXADataSources. (Bug#20242: http://bugs.mysql.com/20242)
* Added connection/datasource property
pinGlobalTxToPhysicalConnection (defaults to false). When set
to true, when using XAConnections, the driver ensures that
operations on a given XID are always routed to the same
physical connection. This allows the XAConnection to support
XA START ... JOIN after XA END has been called, and is also a
workaround for transaction managers that don't maintain thread
affinity for a global transaction (most either always maintain
thread affinity, or have it as a configuration option).
(Bug#20242: http://bugs.mysql.com/20242)
* Better caching of character set converters (per-connection) to
remove a bottleneck for multibyte character sets.
(Bug#20242: http://bugs.mysql.com/20242)
* Fixed ConnectionProperties (and thus some subclasses) are not
serializable, even though some J2EE containers expect them to
be. (Bug#19169: http://bugs.mysql.com/19169)
* Fixed driver fails on non-ASCII platforms. The driver was
assuming that the platform character set would be a superset
of MySQL's latin1 when doing the handshake for authentication,
and when reading error messages. We now use Cp1252 for all
strings sent to the server during the handshake phase, and a
hard-coded mapping of the language systtem variable to the
character set that is used for error messages.
(Bug#18086: http://bugs.mysql.com/18086)
* Fixed can't use XAConnection for local transactions when no
global transaction is in progress.
(Bug#17401: http://bugs.mysql.com/17401)
A.2.8. Changes in MySQL Connector/J 5.0.1 (Not Released)
Not released due to a packaging error
A.2.9. Changes in MySQL Connector/J 5.0.0 (22 December 2005)
Bugs fixed:
* Added support for Connector/MXJ integration via url
subprotocol jdbc:mysql:mxj://....
(Bug#14729: http://bugs.mysql.com/14729)
* Idle timeouts cause XAConnections to whine about rolling
themselves back. (Bug#14729: http://bugs.mysql.com/14729)
* When fix for Bug#14562: http://bugs.mysql.com/14562 was merged
from 3.1.12, added functionality for CallableStatement's
parameter metadata to return correct information for
.getParameterClassName().
(Bug#14729: http://bugs.mysql.com/14729)
* Added service-provider entry to
META-INF/services/java.sql.Driver for JDBC-4.0 support.
(Bug#14729: http://bugs.mysql.com/14729)
* Fuller synchronization of Connection to avoid deadlocks when
using multithreaded frameworks that multithread a single
connection (usually not recommended, but the JDBC spec allows
it anyways), part of fix to
Bug#14972: http://bugs.mysql.com/14972).
(Bug#14729: http://bugs.mysql.com/14729)
* Moved all SQLException constructor usage to a factory in
SQLError (ground-work for JDBC-4.0 SQLState-based exception
classes). (Bug#14729: http://bugs.mysql.com/14729)
* Removed Java5-specific calls to BigDecimal constructor (when
result set value is '', (int)0 was being used as an argument
indirectly via method return value. This signature doesn't
exist prior to Java5.)
(Bug#14729: http://bugs.mysql.com/14729)
* Implementation of Statement.cancel() and
Statement.setQueryTimeout(). Both require MySQL-5.0.0 or newer
server, require a separate connection to issue the KILL QUERY
statement, and in the case of setQueryTimeout() creates an
additional thread to handle the timeout functionality.
Note: Failures to cancel the statement for setQueryTimeout()
may manifest themselves as RuntimeExceptions rather than
failing silently, as there is currently no way to unblock the
thread that is executing the query being cancelled due to
timeout expiration and have it throw the exception instead.
(Bug#14729: http://bugs.mysql.com/14729)
* Return "[VAR]BINARY" for RSMD.getColumnTypeName() when that is
actually the type, and it can be distinguished (MySQL-4.1 and
newer). (Bug#14729: http://bugs.mysql.com/14729)
* Attempt detection of the MySQL type BINARY (it's an alias, so
this isn't always reliable), and use the java.sql.Types.BINARY
type mapping for it.
* Added unit tests for XADatasource, as well as friendlier
exceptions for XA failures compared to the "stock" XAException
(which has no messages).
* If the connection useTimezone is set to true, then also
respect time zone conversions in escape-processed string
literals (for example, "{ts ...}" and "{t ...}").
* Don't allow .setAutoCommit(true), or .commit() or .rollback()
on an XA-managed connection as per the JDBC specification.
* XADataSource implemented (ported from 3.2 branch which won't
be released as a product). Use
com.mysql.jdbc.jdbc2.optional.MysqlXADataSource as your
datasource class name in your application server to utilize XA
transactions in MySQL-5.0.10 and newer.
* Moved -bin-g.jar file into separate debug subdirectory to
avoid confusion.
* Return original column name for RSMD.getColumnName() if the
column was aliased, alias name for .getColumnLabel() (if
aliased), and original table name for .getTableName(). Note
this only works for MySQL-4.1 and newer, as older servers
don't make this information available to clients.
* Setting useJDBCCompliantTimezoneShift=true (it's not the
default) causes the driver to use GMT for all
TIMESTAMP/DATETIME time zones, and the current VM time zone
for any other type that refers to time zones. This feature can
not be used when useTimezone=true to convert between server
and client time zones.
* PreparedStatement.setString() didn't work correctly when
sql_mode on server contained NO_BACKSLASH_ESCAPES and no
characters that needed escaping were present in the string.
* Add one level of indirection of internal representation of
CallableStatement parameter metadata to avoid class not found
issues on JDK-1.3 for ParameterMetadata interface (which
doesn't exist prior to JDBC-3.0).
A.3. Changes in MySQL Connector/J 3.1.x
A.3.1. Changes in MySQL Connector/J 3.1.15 (Not yet released)
Important change: Due to a number of issues with the use of
server-side prepared statements, Connector/J 5.0.5 has disabled
their use by default. The disabling of server-side prepared
statements does not affect the operation of the connector in any
way.
To enable server-side prepared statements you must add the
following configuration property to your connector string:
useServerPrepStmts=true
The default value of this property is false (that is, Connector/J
does not use server-side prepared statements).
Bugs fixed:
* Specifying US-ASCII as the character set in a connection to a
MySQL 4.1 or newer server does not map correctly.
(Bug#24840: http://bugs.mysql.com/24840)
A.3.2. Changes in MySQL Connector/J 3.1.14 (10-19-2006)
Bugs fixed:
* Check and store value for continueBatchOnError property in
constructor of Statements, rather than when executing batches,
so that Connections closed out from underneath statements
don't cause NullPointerExceptions when it's required to check
this property. (Bug#22290: http://bugs.mysql.com/22290)
* Fixed Bug#18258: http://bugs.mysql.com/18258 -
DatabaseMetaData.getTables(), columns() with bad catalog
parameter threw exception rather than return empty result set
(as required by spec).
(Bug#22290: http://bugs.mysql.com/22290)
* Driver now sends numeric 1 or 0 for client-prepared statement
setBoolean() calls instead of '1' or '0'.
(Bug#22290: http://bugs.mysql.com/22290)
* Fixed bug where driver would not advance to next host if
roundRobinLoadBalance=true and the last host in the list is
down. (Bug#22290: http://bugs.mysql.com/22290)
* Driver issues truncation on write exception when it shouldn't
(due to sending big decimal incorrectly to server with
server-side prepared statement).
(Bug#22290: http://bugs.mysql.com/22290)
* Fixed bug when calling stored functions, where parameters
weren't numbered correctly (first parameter is now the return
value, subsequent parameters if specified start at index "2").
(Bug#22290: http://bugs.mysql.com/22290)
* Removed logger autodetection altogether, must now specify
logger explicitly if you want to use a logger other than one
that logs to STDERR. (Bug#21207: http://bugs.mysql.com/21207)
* DDriver throws NPE when tracing prepared statements that have
been closed (in asSQL()).
(Bug#21207: http://bugs.mysql.com/21207)
* ResultSet.getSomeInteger() doesn't work for BIT(>1).
(Bug#21062: http://bugs.mysql.com/21062)
* Escape of quotes in client-side prepared statements parsing
not respected. Patch covers more than bug report, including
NO_BACKSLASH_ESCAPES being set, and stacked quote characters
forms of escaping (that is, '' or "").
(Bug#20888: http://bugs.mysql.com/20888)
* Fixed can't pool server-side prepared statements, exception
raised when re-using them.
(Bug#20687: http://bugs.mysql.com/20687)
* Fixed Updatable result set that contains a BIT column fails
when server-side prepared statements are used.
(Bug#20485: http://bugs.mysql.com/20485)
* Fixed updatable result set throws ClassCastException when
there is row data and moveToInsertRow() is called.
(Bug#20479: http://bugs.mysql.com/20479)
* Fixed ResultSet.getShort() for UNSIGNED TINYINT returns
incorrect values when using server-side prepared statements.
(Bug#20306: http://bugs.mysql.com/20306)
* ReplicationDriver does not always round-robin load balance
depending on URL used for slaves list.
(Bug#19993: http://bugs.mysql.com/19993)
* Fixed calling toString() on ResultSetMetaData for
driver-generated (that is, from DatabaseMetaData method calls,
or from getGeneratedKeys()) result sets would raise a
NullPointerException. (Bug#19993: http://bugs.mysql.com/19993)
* Connection fails to localhost when using timeout and IPv6 is
configured. (Bug#19726: http://bugs.mysql.com/19726)
* ResultSet.getFloatFromString() can't retrieve values near
Float.MIN/MAX_VALUE. (Bug#18880: http://bugs.mysql.com/18880)
* Fixed memory leak with profileSQL=true.
(Bug#16987: http://bugs.mysql.com/16987)
* Fixed NullPointerException in MysqlDataSourceFactory due to
Reference containing RefAddrs with null content.
(Bug#16791: http://bugs.mysql.com/16791)
A.3.3. Changes in MySQL Connector/J 3.1.13 (26 May 2006)
Bugs fixed:
* Fixed PreparedStatement.setObject(int, Object, int) doesn't
respect scale of BigDecimals.
(Bug#19615: http://bugs.mysql.com/19615)
* Fixed ResultSet.wasNull() returns incorrect value when
extracting native string from server-side prepared statement
generated result set. (Bug#19282: http://bugs.mysql.com/19282)
* Fixed invalid classname returned for
ResultSetMetaData.getColumnClassName() for BIGINT type.
(Bug#19282: http://bugs.mysql.com/19282)
* Fixed case where driver wasn't reading server status correctly
when fetching server-side prepared statement rows, which in
some cases could cause warning counts to be off, or multiple
result sets to not be read off the wire.
(Bug#19282: http://bugs.mysql.com/19282)
* Fixed data truncation and getWarnings() only returns last
warning in set. (Bug#18740: http://bugs.mysql.com/18740)
* Fixed aliased column names where length of name > 251 are
corrupted. (Bug#18554: http://bugs.mysql.com/18554)
* Improved performance of retrieving BigDecimal, Time, Timestamp
and Date values from server-side prepared statements by
creating fewer short-lived instances of Strings when the
native type is not an exact match for the requested type.
(Bug#18496: http://bugs.mysql.com/18496)
* Added performance feature, re-writing of batched executes for
Statement.executeBatch() (for all DML statements) and
PreparedStatement.executeBatch() (for INSERTs with VALUE
clauses only). Enable by using "rewriteBatchedStatements=true"
in your JDBC URL. (Bug#18041: http://bugs.mysql.com/18041)
* Fixed issue where server-side prepared statements don't cause
truncation exceptions to be thrown when truncation happens.
(Bug#18041: http://bugs.mysql.com/18041)
* Fixed CallableStatement.registerOutParameter() not working
when some parameters pre-populated. Still waiting for feedback
from JDBC experts group to determine what correct parameter
count from getMetaData() should be, however.
(Bug#17898: http://bugs.mysql.com/17898)
* Fixed calling clearParameters() on a closed prepared statement
causes NPE. (Bug#17587: http://bugs.mysql.com/17587)
* Map "latin1" on MySQL server to CP1252 for MySQL > 4.1.0.
(Bug#17587: http://bugs.mysql.com/17587)
* Added additional accessor and mutator methods on
ConnectionProperties so that DataSource users can use same
naming as regular URL properties.
(Bug#17587: http://bugs.mysql.com/17587)
* Fixed ResultSet.wasNull() not always reset correctly for
booleans when done via conversion for server-side prepared
statements. (Bug#17450: http://bugs.mysql.com/17450)
* Fixed Statement.getGeneratedKeys() throws NullPointerException
when no query has been processed.
(Bug#17099: http://bugs.mysql.com/17099)
* Fixed updatable result set doesn't return AUTO_INCREMENT
values for insertRow() when multiple column primary keys are
used. (the driver was checking for the existence of
single-column primary keys and an autoincrement value > 0
instead of a straightforward isAutoIncrement() check).
(Bug#16841: http://bugs.mysql.com/16841)
* DBMD.getColumns() returns wrong type for BIT.
(Bug#15854: http://bugs.mysql.com/15854)
* lib-nodist directory missing from package breaks out-of-box
build. (Bug#15676: http://bugs.mysql.com/15676)
* Fixed issue with ReplicationConnection incorrectly copying
state, doesn't transfer connection context correctly when
transitioning between the same read-only states.
(Bug#15570: http://bugs.mysql.com/15570)
* No "dos" character set in MySQL > 4.1.0.
(Bug#15544: http://bugs.mysql.com/15544)
* INOUT parameter does not store IN value.
(Bug#15464: http://bugs.mysql.com/15464)
* PreparedStatement.setObject() serializes BigInteger as object,
rather than sending as numeric value (and is thus not
complementary to .getObject() on an UNSIGNED LONG type).
(Bug#15383: http://bugs.mysql.com/15383)
* Fixed issue where driver was unable to initialize character
set mapping tables. Removed reliance on .properties files to
hold this information, as it turns out to be too problematic
to code around class loader hierarchies that change depending
on how an application is deployed. Moved information back into
the CharsetMapping class.
(Bug#14938: http://bugs.mysql.com/14938)
* Exception thrown for new decimal type when using updatable
result sets. (Bug#14609: http://bugs.mysql.com/14609)
* Driver now aware of fix for BIT type metadata that went into
MySQL-5.0.21 for server not reporting length consistently .
(Bug#13601: http://bugs.mysql.com/13601)
* Added support for Apache Commons logging, use
"com.mysql.jdbc.log.CommonsLogger" as the value for the
"logger" configuration property.
(Bug#13469: http://bugs.mysql.com/13469)
* Fixed driver trying to call methods that don't exist on older
and newer versions of Log4j. The fix is not trying to
auto-detect presence of log4j, too many different incompatible
versions out there in the wild to do this reliably.
If you relied on autodetection before, you will need to add
"logger=com.mysql.jdbc.log.Log4JLogger" to your JDBC URL to
enable Log4J usage, or alternatively use the new
"CommonsLogger" class to take care of this.
(Bug#13469: http://bugs.mysql.com/13469)
* LogFactory now prepends "com.mysql.jdbc.log" to log class name
if it can't be found as-specified. This allows you to use
"short names" for the built-in log factories, for example
"logger=CommonsLogger" instead of
"logger=com.mysql.jdbc.log.CommonsLogger".
(Bug#13469: http://bugs.mysql.com/13469)
* ResultSet.getShort() for UNSIGNED TINYINT returned wrong
values. (Bug#11874: http://bugs.mysql.com/11874)
A.3.4. Changes in MySQL Connector/J 3.1.12 (30 November 2005)
Bugs fixed:
* Process escape tokens in Connection.prepareStatement(...). You
can disable this behavior by setting the JDBC URL
configuration property processEscapeCodesForPrepStmts to
false. (Bug#15141: http://bugs.mysql.com/15141)
* Usage advisor complains about unreferenced columns, even
though they've been referenced.
(Bug#15065: http://bugs.mysql.com/15065)
* Driver incorrectly closes streams passed as arguments to
PreparedStatements. Reverts to legacy behavior by setting the
JDBC configuration property autoClosePStmtStreams to true
(also included in the 3-0-Compat configuration "bundle").
(Bug#15024: http://bugs.mysql.com/15024)
* Deadlock while closing server-side prepared statements from
multiple threads sharing one connection.
(Bug#14972: http://bugs.mysql.com/14972)
* Unable to initialize character set mapping tables (due to J2EE
classloader differences).
(Bug#14938: http://bugs.mysql.com/14938)
* Escape processor replaces quote character in quoted string
with string delimiter.
(Bug#14909: http://bugs.mysql.com/14909)
* DatabaseMetaData.getColumns() doesn't return TABLE_NAME
correctly. (Bug#14815: http://bugs.mysql.com/14815)
* storesMixedCaseIdentifiers() returns false
(Bug#14562: http://bugs.mysql.com/14562)
* storesLowerCaseIdentifiers() returns true
(Bug#14562: http://bugs.mysql.com/14562)
* storesMixedCaseQuotedIdentifiers() returns false
(Bug#14562: http://bugs.mysql.com/14562)
* storesMixedCaseQuotedIdentifiers() returns true
(Bug#14562: http://bugs.mysql.com/14562)
* If lower_case_table_names=0 (on server):
+ storesLowerCaseIdentifiers() returns false
+ storesLowerCaseQuotedIdentifiers() returns false
+ storesMixedCaseIdentifiers() returns true
+ storesMixedCaseQuotedIdentifiers() returns true
+ storesUpperCaseIdentifiers() returns false
+ storesUpperCaseQuotedIdentifiers() returns true
(Bug#14562: http://bugs.mysql.com/14562)
* storesUpperCaseIdentifiers() returns false
(Bug#14562: http://bugs.mysql.com/14562)
* storesUpperCaseQuotedIdentifiers() returns true
(Bug#14562: http://bugs.mysql.com/14562)
* If lower_case_table_names=1 (on server):
+ storesLowerCaseIdentifiers() returns true
+ storesLowerCaseQuotedIdentifiers() returns true
+ storesMixedCaseIdentifiers() returns false
+ storesMixedCaseQuotedIdentifiers() returns false
+ storesUpperCaseIdentifiers() returns false
+ storesUpperCaseQuotedIdentifiers() returns true
(Bug#14562: http://bugs.mysql.com/14562)
* storesLowerCaseQuotedIdentifiers() returns true
(Bug#14562: http://bugs.mysql.com/14562)
* Fixed DatabaseMetaData.stores*Identifiers():
+ If lower_case_table_names=0 (on server):
o storesLowerCaseIdentifiers() returns false
o storesLowerCaseQuotedIdentifiers() returns false
o storesMixedCaseIdentifiers() returns true
o storesMixedCaseQuotedIdentifiers() returns true
o storesUpperCaseIdentifiers() returns false
o storesUpperCaseQuotedIdentifiers() returns true
+ If lower_case_table_names=1 (on server):
o storesLowerCaseIdentifiers() returns true
o storesLowerCaseQuotedIdentifiers() returns true
o storesMixedCaseIdentifiers() returns false
o storesMixedCaseQuotedIdentifiers() returns false
o storesUpperCaseIdentifiers() returns false
o storesUpperCaseQuotedIdentifiers() returns true
(Bug#14562: http://bugs.mysql.com/14562)
* storesMixedCaseIdentifiers() returns true
(Bug#14562: http://bugs.mysql.com/14562)
* storesLowerCaseQuotedIdentifiers() returns false
(Bug#14562: http://bugs.mysql.com/14562)
* Java type conversion may be incorrect for MEDIUMINT.
(Bug#14562: http://bugs.mysql.com/14562)
* storesLowerCaseIdentifiers() returns false
(Bug#14562: http://bugs.mysql.com/14562)
* Added configuration property useGmtMillisForDatetimes which
when set to true causes ResultSet.getDate(), .getTimestamp()
to return correct millis-since GMT when .getTime() is called
on the return value (currently default is false for legacy
behavior). (Bug#14562: http://bugs.mysql.com/14562)
* Extraneous sleep on autoReconnect.
(Bug#13775: http://bugs.mysql.com/13775)
* Reconnect during middle of executeBatch() should not occur if
autoReconnect is enabled.
(Bug#13255: http://bugs.mysql.com/13255)
* maxQuerySizeToLog is not respected. Added logging of bound
values for execute() phase of server-side prepared statements
when profileSQL=true as well.
(Bug#13048: http://bugs.mysql.com/13048)
* OpenOffice expects DBMD.supportsIntegrityEnhancementFacility()
to return true if foreign keys are supported by the
datasource, even though this method also covers support for
check constraints, which MySQL doesn't have. Setting the
configuration property
overrideSupportsIntegrityEnhancementFacility to true causes
the driver to return true for this method.
(Bug#12975: http://bugs.mysql.com/12975)
* Added com.mysql.jdbc.testsuite.url.default system property to
set default JDBC url for testsuite (to speed up bug resolution
when I'm working in Eclipse).
(Bug#12975: http://bugs.mysql.com/12975)
* logSlowQueries should give better info.
(Bug#12230: http://bugs.mysql.com/12230)
* Don't increase timeout for failover/reconnect.
(Bug#6577: http://bugs.mysql.com/6577)
* Fixed client-side prepared statement bug with embedded ?
characters inside quoted identifiers (it was recognized as a
placeholder, when it was not).
* Don't allow executeBatch() for CallableStatements with
registered OUT/INOUT parameters (JDBC compliance).
* Fall back to platform-encoding for URLDecoder.decode() when
parsing driver URL properties if the platform doesn't have a
two-argument version of this method.
A.3.5. Changes in MySQL Connector/J 3.1.11 (07 October 2005)
Bugs fixed:
* The configuration property sessionVariables now allows you to
specify variables that start with the "@" sign.
(Bug#13453: http://bugs.mysql.com/13453)
* URL configuration parameters don't allow "&" or "=" in their
values. The JDBC driver now parses configuration parameters as
if they are encoded using the
application/x-www-form-urlencoded format as specified by
java.net.URLDecoder
(http://java.sun.com/j2se/1.5.0/docs/api/java/net/URLDecoder.h
tml).
If the "%" character is present in a configuration property,
it must now be represented as %25, which is the encoded form
of "%" when using application/x-www-form-urlencoded encoding.
(Bug#13453: http://bugs.mysql.com/13453)
* Workaround for Bug#13374: http://bugs.mysql.com/13374:
ResultSet.getStatement() on closed result set returns NULL (as
per JDBC 4.0 spec, but not backward-compatible). Set the
connection property retainStatementAfterResultSetClose to true
to be able to retrieve a ResultSet's statement after the
ResultSet has been closed via .getStatement() (the default is
false, to be JDBC-compliant and to reduce the chance that code
using JDBC leaks Statement instances).
(Bug#13277: http://bugs.mysql.com/13277)
* ResultSetMetaData from Statement.getGeneratedKeys() caused a
NullPointerException to be thrown whenever a method that
required a connection reference was called.
(Bug#13277: http://bugs.mysql.com/13277)
* Backport of VAR[BINARY|CHAR] [BINARY] types detection from 5.0
branch. (Bug#13277: http://bugs.mysql.com/13277)
* Fixed NullPointerException when converting catalog parameter
in many DatabaseMetaDataMethods to byte[]s (for the result
set) when the parameter is null. (null isn't technically
allowed by the JDBC specification, but we've historically
allowed it). (Bug#13277: http://bugs.mysql.com/13277)
* Backport of Field class,
ResultSetMetaData.getColumnClassName(), and
ResultSet.getObject(int) changes from 5.0 branch to fix
behavior surrounding VARCHAR BINARY/VARBINARY and related
types. (Bug#13277: http://bugs.mysql.com/13277)
* Read response in MysqlIO.sendFileToServer(), even if the local
file can't be opened, otherwise next query issued will fail,
because it's reading the response to the empty LOAD DATA
INFILE packet sent to the server.
(Bug#13277: http://bugs.mysql.com/13277)
* When gatherPerfMetrics is enabled for servers older than
4.1.0, a NullPointerException is thrown from the constructor
of ResultSet if the query doesn't use any tables.
(Bug#13043: http://bugs.mysql.com/13043)
* java.sql.Types.OTHER returned for BINARY and VARBINARY columns
when using DatabaseMetaData.getColumns().
(Bug#12970: http://bugs.mysql.com/12970)
* ServerPreparedStatement.getBinding() now checks if the
statement is closed before attempting to reference the list of
parameter bindings, to avoid throwing a NullPointerException.
(Bug#12970: http://bugs.mysql.com/12970)
* Tokenizer for = in URL properties was causing
sessionVariables=.... to be parameterized incorrectly.
(Bug#12753: http://bugs.mysql.com/12753)
* cp1251 incorrectly mapped to win1251 for servers newer than
4.0.x. (Bug#12752: http://bugs.mysql.com/12752)
* getExportedKeys() (Bug#12541: http://bugs.mysql.com/12541)
* Specifying a catalog works as stated in the API docs.
(Bug#12541: http://bugs.mysql.com/12541)
* Specifying NULL means that catalog will not be used to filter
the results (thus all databases will be searched), unless
you've set nullCatalogMeansCurrent=true in your JDBC URL
properties. (Bug#12541: http://bugs.mysql.com/12541)
* getIndexInfo() (Bug#12541: http://bugs.mysql.com/12541)
* getProcedures() (and thus indirectly getProcedureColumns())
(Bug#12541: http://bugs.mysql.com/12541)
* getImportedKeys() (Bug#12541: http://bugs.mysql.com/12541)
* Specifying "" means "current" catalog, even though this isn't
quite JDBC spec compliant, it's there for legacy users.
(Bug#12541: http://bugs.mysql.com/12541)
* getCrossReference() (Bug#12541: http://bugs.mysql.com/12541)
* Added Connection.isMasterConnection() for clients to be able
to determine if a multi-host master/slave connection is
connected to the first host in the list.
(Bug#12541: http://bugs.mysql.com/12541)
* getColumns() (Bug#12541: http://bugs.mysql.com/12541)
* Handling of catalog argument in
DatabaseMetaData.getIndexInfo(), which also means changes to
the following methods in DatabaseMetaData:
+ getBestRowIdentifier()
+ getColumns()
+ getCrossReference()
+ getExportedKeys()
+ getImportedKeys()
+ getIndexInfo()
+ getPrimaryKeys()
+ getProcedures() (and thus indirectly
getProcedureColumns())
+ getTables()
The catalog argument in all of these methods now behaves in
the following way:
+ Specifying NULL means that catalog will not be used to
filter the results (thus all databases will be searched),
unless you've set nullCatalogMeansCurrent=true in your
JDBC URL properties.
+ Specifying "" means "current" catalog, even though this
isn't quite JDBC spec compliant, it's there for legacy
users.
+ Specifying a catalog works as stated in the API docs.
+ Made Connection.clientPrepare() available from "wrapped"
connections in the jdbc2.optional package (connections
built by ConnectionPoolDataSource instances).
(Bug#12541: http://bugs.mysql.com/12541)
* getBestRowIdentifier()
(Bug#12541: http://bugs.mysql.com/12541)
* Made Connection.clientPrepare() available from "wrapped"
connections in the jdbc2.optional package (connections built
by ConnectionPoolDataSource instances).
(Bug#12541: http://bugs.mysql.com/12541)
* getTables() (Bug#12541: http://bugs.mysql.com/12541)
* getPrimaryKeys() (Bug#12541: http://bugs.mysql.com/12541)
* Connection.prepareCall() is database name case-sensitive (on
Windows systems). (Bug#12417: http://bugs.mysql.com/12417)
* explainSlowQueries hangs with server-side prepared statements.
(Bug#12229: http://bugs.mysql.com/12229)
* Properties shared between master and slave with replication
connection. (Bug#12218: http://bugs.mysql.com/12218)
* Geometry types not handled with server-side prepared
statements. (Bug#12104: http://bugs.mysql.com/12104)
* maxPerformance.properties mis-spells "elideSetAutoCommits".
(Bug#11976: http://bugs.mysql.com/11976)
* ReplicationConnection won't switch to slave, throws "Catalog
can't be null" exception.
(Bug#11879: http://bugs.mysql.com/11879)
* Pstmt.setObject(...., Types.BOOLEAN) throws exception.
(Bug#11798: http://bugs.mysql.com/11798)
* Escape tokenizer doesn't respect stacked single quotes for
escapes. (Bug#11797: http://bugs.mysql.com/11797)
* GEOMETRY type not recognized when using server-side prepared
statements. (Bug#11797: http://bugs.mysql.com/11797)
* Foreign key information that is quoted is parsed incorrectly
when DatabaseMetaData methods use that information.
(Bug#11781: http://bugs.mysql.com/11781)
* The sendBlobChunkSize property is now clamped to
max_allowed_packet with consideration of stream buffer size
and packet headers to avoid PacketTooBigExceptions when
max_allowed_packet is similar in size to the default
sendBlobChunkSize which is 1M.
(Bug#11781: http://bugs.mysql.com/11781)
* CallableStatement.clearParameters() now clears resources
associated with INOUT/OUTPUT parameters as well as INPUT
parameters. (Bug#11781: http://bugs.mysql.com/11781)
* Fixed regression caused by fix for
Bug#11552: http://bugs.mysql.com/11552 that caused driver to
return incorrect values for unsigned integers when those
integers where within the range of the positive signed type.
(Bug#11663: http://bugs.mysql.com/11663)
* Moved source code to Subversion repository.
(Bug#11663: http://bugs.mysql.com/11663)
* Incorrect generation of testcase scripts for server-side
prepared statements. (Bug#11663: http://bugs.mysql.com/11663)
* Fixed statements generated for testcases missing ; for "plain"
statements. (Bug#11629: http://bugs.mysql.com/11629)
* Spurious ! on console when character encoding is utf8.
(Bug#11629: http://bugs.mysql.com/11629)
* StringUtils.getBytes() doesn't work when using multi-byte
character encodings and a length in characters is specified.
(Bug#11614: http://bugs.mysql.com/11614)
* DBMD.storesLower/Mixed/UpperIdentifiers() reports incorrect
values for servers deployed on Windows.
(Bug#11575: http://bugs.mysql.com/11575)
* Reworked Field class, *Buffer, and MysqlIO to be aware of
field lengths > Integer.MAX_VALUE.
(Bug#11498: http://bugs.mysql.com/11498)
* Escape processor didn't honor strings demarcated with double
quotes. (Bug#11498: http://bugs.mysql.com/11498)
* Updated DBMD.supportsCorrelatedQueries() to return true for
versions > 4.1, supportsGroupByUnrelated() to return true and
getResultSetHoldability() to return HOLD_CURSORS_OVER_COMMIT.
(Bug#11498: http://bugs.mysql.com/11498)
* Lifted restriction of changing streaming parameters with
server-side prepared statements. As long as all streaming
parameters were set before execution, .clearParameters() does
not have to be called. (due to limitation of client/server
protocol, prepared statements can not reset individual stream
data on the server side).
(Bug#11498: http://bugs.mysql.com/11498)
* ResultSet.moveToCurrentRow() fails to work when preceded by a
call to ResultSet.moveToInsertRow().
(Bug#11190: http://bugs.mysql.com/11190)
* VARBINARY data corrupted when using server-side prepared
statements and .setBytes().
(Bug#11115: http://bugs.mysql.com/11115)
* Statement.getWarnings() fails with NPE if statement has been
closed. (Bug#10630: http://bugs.mysql.com/10630)
* Only get char[] from SQL in PreparedStatement.ParseInfo() when
needed. (Bug#10630: http://bugs.mysql.com/10630)
A.3.6. Changes in MySQL Connector/J 3.1.10 (23 June 2005)
Bugs fixed:
* Initial implemention of ParameterMetadata for
PreparedStatement.getParameterMetadata(). Only works fully for
CallableStatements, as current server-side prepared statements
return every parameter as a VARCHAR type.
* Fixed connecting without a database specified raised an
exception in MysqlIO.changeDatabaseTo().
A.3.7. Changes in MySQL Connector/J 3.1.9 (22 June 2005)
Bugs fixed:
* Production package doesn't include JBoss integration classes.
(Bug#11411: http://bugs.mysql.com/11411)
* Removed nonsensical "costly type conversion" warnings when
using usage advisor. (Bug#11411: http://bugs.mysql.com/11411)
* Fixed PreparedStatement.setClob() not accepting null as a
parameter. (Bug#11360: http://bugs.mysql.com/11360)
* Connector/J dumping query into SQLException twice.
(Bug#11360: http://bugs.mysql.com/11360)
* autoReconnect ping causes exception on connection startup.
(Bug#11259: http://bugs.mysql.com/11259)
* Connection.setCatalog() is now aware of the
useLocalSessionState configuration property, which when set to
true will prevent the driver from sending USE ... to the
server if the requested catalog is the same as the current
catalog. (Bug#11115: http://bugs.mysql.com/11115)
* 3-0-Compat --- Compatibility with Connector/J 3.0.x
functionality (Bug#11115: http://bugs.mysql.com/11115)
* maxPerformance --- maximum performance without being reckless
(Bug#11115: http://bugs.mysql.com/11115)
* solarisMaxPerformance --- maximum performance for Solaris,
avoids syscalls where it can
(Bug#11115: http://bugs.mysql.com/11115)
* Added maintainTimeStats configuration property (defaults to
true), which tells the driver whether or not to keep track of
the last query time and the last successful packet sent to the
server's time. If set to false, removes two syscalls per
query. (Bug#11115: http://bugs.mysql.com/11115)
* VARBINARY data corrupted when using server-side prepared
statements and ResultSet.getBytes().
(Bug#11115: http://bugs.mysql.com/11115)
* Added the following configuration bundles, use one or many via
the useConfigs configuration property:
+ maxPerformance --- maximum performance without being
reckless
+ solarisMaxPerformance --- maximum performance for
Solaris, avoids syscalls where it can
+ 3-0-Compat --- Compatibility with Connector/J 3.0.x
functionality
(Bug#11115: http://bugs.mysql.com/11115)
* Try to handle OutOfMemoryErrors more gracefully. Although not
much can be done, they will in most cases close the connection
they happened on so that further operations don't run into a
connection in some unknown state. When an OOM has happened,
any further operations on the connection will fail with a
"Connection closed" exception that will also list the OOM
exception as the reason for the implicit connection close
event. (Bug#10850: http://bugs.mysql.com/10850)
* Setting cachePrepStmts=true now causes the Connection to also
cache the check the driver performs to determine if a prepared
statement can be server-side or not, as well as caches
server-side prepared statements for the lifetime of a
connection. As before, the prepStmtCacheSize parameter
controls the size of these caches.
(Bug#10850: http://bugs.mysql.com/10850)
* Don't send COM_RESET_STMT for each execution of a server-side
prepared statement if it isn't required.
(Bug#10850: http://bugs.mysql.com/10850)
* 0-length streams not sent to server when using server-side
prepared statements. (Bug#10850: http://bugs.mysql.com/10850)
* Driver detects if you're running MySQL-5.0.7 or later, and
does not scan for LIMIT ?[,?] in statements being prepared, as
the server supports those types of queries now.
(Bug#10850: http://bugs.mysql.com/10850)
* Reorganized directory layout. Sources now are in src folder.
Don't pollute parent directory when building, now output goes
to ./build, distribution goes to ./dist.
(Bug#10496: http://bugs.mysql.com/10496)
* Added support/bug hunting feature that generates .sql test
scripts to STDERR when autoGenerateTestcaseScript is set to
true. (Bug#10496: http://bugs.mysql.com/10496)
* SQLException is thrown when using property characterSetResults
with cp932 or eucjpms.
(Bug#10496: http://bugs.mysql.com/10496)
* The datatype returned for TINYINT(1) columns when
tinyInt1isBit=true (the default) can be switched between
Types.BOOLEAN and Types.BIT using the new configuration
property transformedBitIsBoolean, which defaults to false. If
set to false (the default), DatabaseMetaData.getColumns() and
ResultSetMetaData.getColumnType() will return Types.BOOLEAN
for TINYINT(1) columns. If true, Types.BOOLEAN will be
returned instead. Regardless of this configuration property,
if tinyInt1isBit is enabled, columns with the type TINYINT(1)
will be returned as java.lang.Boolean instances from
ResultSet.getObject(...), and
ResultSetMetaData.getColumnClassName() will return
java.lang.Boolean. (Bug#10485: http://bugs.mysql.com/10485)
* SQLException thrown when retrieving YEAR(2) with
ResultSet.getString(). The driver will now always treat YEAR
types as java.sql.Dates and return the correct values for
getString(). Alternatively, the yearIsDateType connection
property can be set to false and the values will be treated as
SHORTs. (Bug#10485: http://bugs.mysql.com/10485)
* Driver doesn't support {?=CALL(...)} for calling stored
functions. This involved adding support for function retrieval
to DatabaseMetaData.getProcedures() and getProcedureColumns()
as well. (Bug#10310: http://bugs.mysql.com/10310)
* Unsigned SMALLINT treated as signed for ResultSet.getInt(),
fixed all cases for UNSIGNED integer values and server-side
prepared statements, as well as ResultSet.getObject() for
UNSIGNED TINYINT. (Bug#10156: http://bugs.mysql.com/10156)
* Made ServerPreparedStatement.asSql() work correctly so
auto-explain functionality would work with server-side
prepared statements. (Bug#10155: http://bugs.mysql.com/10155)
* Double quotes not recognized when parsing client-side prepared
statements. (Bug#10155: http://bugs.mysql.com/10155)
* Made JDBC2-compliant wrappers public in order to allow access
to vendor extensions. (Bug#10155: http://bugs.mysql.com/10155)
* DatabaseMetaData.supportsMultipleOpenResults() now returns
true. The driver has supported this for some time, DBMD just
missed that fact. (Bug#10155: http://bugs.mysql.com/10155)
* Cleaned up logging of profiler events, moved code to dump a
profiler event as a string to com.mysql.jdbc.log.LogUtils so
that third parties can use it.
(Bug#10155: http://bugs.mysql.com/10155)
* Made enableStreamingResults() visible on
com.mysql.jdbc.jdbc2.optional.StatementWrapper.
(Bug#10155: http://bugs.mysql.com/10155)
* Actually write manifest file to correct place so it ends up in
the binary jar file. (Bug#10144: http://bugs.mysql.com/10144)
* Added createDatabaseIfNotExist property (default is false),
which will cause the driver to ask the server to create the
database specified in the URL if it doesn't exist. You must
have the appropriate privileges for database creation for this
to work. (Bug#10144: http://bugs.mysql.com/10144)
* Memory leak in ServerPreparedStatement if serverPrepare()
fails. (Bug#10144: http://bugs.mysql.com/10144)
* com.mysql.jdbc.PreparedStatement.ParseInfo does unnecessary
call to toCharArray(). (Bug#9064: http://bugs.mysql.com/9064)
* Driver now correctly uses CP932 if available on the server for
Windows-31J, CP932 and MS932 java encoding names, otherwise it
resorts to SJIS, which is only a close approximation.
Currently only MySQL-5.0.3 and newer (and MySQL-4.1.12 or .13,
depending on when the character set gets backported) can
reliably support any variant of CP932.
* Overhaul of character set configuration, everything now lives
in a properties file.
A.3.8. Changes in MySQL Connector/J 3.1.8 (14 April 2005)
Bugs fixed:
* Should accept null for catalog (meaning use current) in DBMD
methods, even though it's not JDBC-compliant for legacy's
sake. Disable by setting connection property
nullCatalogMeansCurrent to false (which will be the default
value in C/J 3.2.x). (Bug#9917: http://bugs.mysql.com/9917)
* Fixed driver not returning true for -1 when
ResultSet.getBoolean() was called on result sets returned from
server-side prepared statements.
(Bug#9778: http://bugs.mysql.com/9778)
* Added a Manifest.MF file with implementation information to
the .jar file. (Bug#9778: http://bugs.mysql.com/9778)
* More tests in Field.isOpaqueBinary() to distinguish opaque
binary (that is, fields with type CHAR(n) and CHARACTER SET
BINARY) from output of various scalar and aggregate functions
that return strings. (Bug#9778: http://bugs.mysql.com/9778)
* DBMD.getTables() shouldn't return tables if views are asked
for, even if the database version doesn't support views.
(Bug#9778: http://bugs.mysql.com/9778)
* Should accept null for name patterns in DBMD (meaning "%"),
even though it isn't JDBC compliant, for legacy's sake.
Disable by setting connection property
nullNamePatternMatchesAll to false (which will be the default
value in C/J 3.2.x). (Bug#9769: http://bugs.mysql.com/9769)
* Then fallback to our STDERR logging.
(Bug#9704: http://bugs.mysql.com/9704)
* The performance metrics feature now gathers information about
number of tables referenced in a SELECT.
(Bug#9704: http://bugs.mysql.com/9704)
* The logging system is now automatically configured. If the
value has been set by the user, via the URL property logger or
the system property com.mysql.jdbc.logger, then use that,
otherwise, autodetect it using the following steps:
1. Log4j, if it's available,
2. Then JDK1.4 logging,
3. Then fallback to our STDERR logging.
(Bug#9704: http://bugs.mysql.com/9704)
* Then JDK1.4 logging, (Bug#9704: http://bugs.mysql.com/9704)
* Log4j, if it's available,
(Bug#9704: http://bugs.mysql.com/9704)
* Statement.getMoreResults() could throw NPE when existing
result set was .close()d.
(Bug#9704: http://bugs.mysql.com/9704)
* Stored procedures with DECIMAL parameters with storage
specifications that contained "," in them would fail.
(Bug#9682: http://bugs.mysql.com/9682)
* PreparedStatement.setObject(int, Object, int type, int scale)
now uses scale value for BigDecimal instances.
(Bug#9682: http://bugs.mysql.com/9682)
* Added support for the c3p0 connection pool's
(http://c3p0.sf.net/) validation/connection checker interface
which uses the lightweight COM_PING call to the server if
available. To use it, configure your c3p0 connection pool's
connectionTesterClassName property to use
com.mysql.jdbc.integration.c3p0.MysqlConnectionTester.
(Bug#9320: http://bugs.mysql.com/9320)
* PreparedStatement.getMetaData() inserts blank row in database
under certain conditions when not using server-side prepared
statements. (Bug#9320: http://bugs.mysql.com/9320)
* Better detection of LIMIT inside/outside of quoted strings so
that the driver can more correctly determine whether a
prepared statement can be prepared on the server or not.
(Bug#9320: http://bugs.mysql.com/9320)
* Connection.canHandleAsPreparedStatement() now makes "best
effort" to distinguish LIMIT clauses with placeholders in them
from ones without in order to have fewer false positives when
generating work-arounds for statements the server cannot
currently handle as server-side prepared statements.
(Bug#9320: http://bugs.mysql.com/9320)
* Fixed build.xml to not compile log4j logging if log4j not
available. (Bug#9320: http://bugs.mysql.com/9320)
* Added finalizers to ResultSet and Statement implementations to
be JDBC spec-compliant, which requires that if not explicitly
closed, these resources should be closed upon garbage
collection. (Bug#9319: http://bugs.mysql.com/9319)
* Stored procedures with same name in different databases
confuse the driver when it tries to determine parameter
counts/types. (Bug#9319: http://bugs.mysql.com/9319)
* A continuation of Bug#8868: http://bugs.mysql.com/8868, where
functions used in queries that should return non-string types
when resolved by temporary tables suddenly become opaque
binary strings (work-around for server limitation). Also fixed
fields with type of CHAR(n) CHARACTER SET BINARY to return
correct/matching classes for RSMD.getColumnClassName() and
ResultSet.getObject(). (Bug#9236: http://bugs.mysql.com/9236)
* Cannot use UTF-8 for characterSetResults configuration
property. (Bug#9206: http://bugs.mysql.com/9206)
* PreparedStatement.addBatch() doesn't work with server-side
prepared statements and streaming BINARY data.
(Bug#9040: http://bugs.mysql.com/9040)
* ServerPreparedStatements now correctly "stream" BLOB/CLOB data
to the server. You can configure the threshold chunk size
using the JDBC URL property blobSendChunkSize (the default is
1MB). (Bug#8868: http://bugs.mysql.com/8868)
* DATE_FORMAT()
(http://dev.mysql.com/doc/refman/4.1/en/date-and-time-function
s.html#function_date-format) queries returned as BLOBs from
getObject(). (Bug#8868: http://bugs.mysql.com/8868)
* Server-side session variables can be preset at connection time
by passing them as a comma-delimited list for the connection
property sessionVariables.
(Bug#8868: http://bugs.mysql.com/8868)
* BlobFromLocator now uses correct identifier quoting when
generating prepared statements.
(Bug#8868: http://bugs.mysql.com/8868)
* Fixed regression in ping() for users using autoReconnect=true.
(Bug#8868: http://bugs.mysql.com/8868)
* Check for empty strings ('') when converting CHAR/VARCHAR
column data to numbers, throw exception if
emptyStringsConvertToZero configuration property is set to
false (for backward-compatibility with 3.0, it is now set to
true by default, but will most likely default to false in
3.2). (Bug#8803: http://bugs.mysql.com/8803)
* DATA_TYPE column from DBMD.getBestRowIdentifier() causes
ArrayIndexOutOfBoundsException when accessed (and in fact,
didn't return any value).
(Bug#8803: http://bugs.mysql.com/8803)
* DBMD.supportsMixedCase*Identifiers() returns wrong value on
servers running on case-sensitive filesystems.
(Bug#8800: http://bugs.mysql.com/8800)
* DBMD.supportsResultSetConcurrency() not returning true for
forward-only/read-only result sets (we obviously support
this). (Bug#8792: http://bugs.mysql.com/8792)
* Fixed ResultSet.getTime() on a NULL value for server-side
prepared statements throws NPE.
* Made Connection.ping() a public method.
* Added support for new precision-math DECIMAL type in MySQL
5.0.3 and up.
* Fixed DatabaseMetaData.getTables() returning views when they
were not asked for as one of the requested table types.
A.3.9. Changes in MySQL Connector/J 3.1.7 (18 February 2005)
Bugs fixed:
* PreparedStatements not creating streaming result sets.
(Bug#8487: http://bugs.mysql.com/8487)
* Don't pass NULL to String.valueOf() in
ResultSet.getNativeConvertToString(), as it stringifies it
(that is, returns null), which is not correct for the method
in question. (Bug#8487: http://bugs.mysql.com/8487)
* Fixed NPE in ResultSet.realClose() when using usage advisor
and result set was already closed.
(Bug#8428: http://bugs.mysql.com/8428)
* ResultSet.getString() doesn't maintain format stored on
server, bug fix only enabled when noDatetimeStringSync
property is set to true (the default is false).
(Bug#8428: http://bugs.mysql.com/8428)
* Added support for BIT type in MySQL-5.0.3. The driver will
treat BIT(1-8) as the JDBC standard BIT type (which maps to
java.lang.Boolean), as the server does not currently send
enough information to determine the size of a bitfield when <
9 bits are declared. BIT(>9) will be treated as VARBINARY, and
will return byte[] when getObject() is called.
(Bug#8424: http://bugs.mysql.com/8424)
* Added useLocalSessionState configuration property, when set to
true the JDBC driver trusts that the application is
well-behaved and only sets autocommit and transaction
isolation levels using the methods provided on
java.sql.Connection, and therefore can manipulate these values
in many cases without incurring round-trips to the database
server. (Bug#8424: http://bugs.mysql.com/8424)
* Added enableStreamingResults() to Statement for connection
pool implementations that check Statement.setFetchSize() for
specification-compliant values. Call
Statement.setFetchSize(>=0) to disable the streaming results
for that statement. (Bug#8424: http://bugs.mysql.com/8424)
* ResultSet.getBigDecimal() throws exception when rounding would
need to occur to set scale. The driver now chooses a rounding
mode of "half up" if non-rounding BigDecimal.setScale() fails.
(Bug#8424: http://bugs.mysql.com/8424)
* Fixed synchronization issue with
ServerPreparedStatement.serverPrepare() that could cause
deadlocks/crashes if connection was shared between threads.
(Bug#8096: http://bugs.mysql.com/8096)
* Emulated locators corrupt binary data when using server-side
prepared statements. (Bug#8096: http://bugs.mysql.com/8096)
* Infinite recursion when "falling back" to master in failover
configuration. (Bug#7952: http://bugs.mysql.com/7952)
* Disable multi-statements (if enabled) for MySQL-4.1 versions
prior to version 4.1.10 if the query cache is enabled, as the
server returns wrong results in this configuration.
(Bug#7952: http://bugs.mysql.com/7952)
* Removed dontUnpackBinaryResults functionality, the driver now
always stores results from server-side prepared statements as
is from the server and unpacks them on demand.
(Bug#7952: http://bugs.mysql.com/7952)
* Fixed duplicated code in configureClientCharset() that
prevented useOldUTF8Behavior=true from working properly.
(Bug#7952: http://bugs.mysql.com/7952)
* Added holdResultsOpenOverStatementClose property (default is
false), that keeps result sets open over statement.close() or
new execution on same statement (suggested by Kevin Burton).
(Bug#7715: http://bugs.mysql.com/7715)
* Detect new sql_mode variable in string form (it used to be
integer) and adjust quoting method for strings appropriately.
(Bug#7715: http://bugs.mysql.com/7715)
* Timestamps converted incorrectly to strings with server-side
prepared statements and updatable result sets.
(Bug#7715: http://bugs.mysql.com/7715)
* Timestamp key column data needed _binary stripped for
UpdatableResultSet.refreshRow().
(Bug#7686: http://bugs.mysql.com/7686)
* Choose correct "direction" to apply time adjustments when both
client and server are in GMT time zone when using
ResultSet.get(..., cal) and PreparedStatement.set(...., cal).
(Bug#4718: http://bugs.mysql.com/4718)
* Remove _binary introducer from parameters used as in/out
parameters in CallableStatement.
(Bug#4718: http://bugs.mysql.com/4718)
* Always return byte[]s for output parameters registered as
*BINARY. (Bug#4718: http://bugs.mysql.com/4718)
* By default, the driver now scans SQL you are preparing via all
variants of Connection.prepareStatement() to determine if it
is a supported type of statement to prepare on the server
side, and if it is not supported by the server, it instead
prepares it as a client-side emulated prepared statement. You
can disable this by passing emulateUnsupportedPstmts=false in
your JDBC URL. (Bug#4718: http://bugs.mysql.com/4718)
* Added dontTrackOpenResources option (default is false, to be
JDBC compliant), which helps with memory use for
non-well-behaved apps (that is, applications that don't close
Statement objects when they should).
(Bug#4718: http://bugs.mysql.com/4718)
* Send correct value for "boolean" true to server for
PreparedStatement.setObject(n, "true", Types.BIT).
(Bug#4718: http://bugs.mysql.com/4718)
* Fixed bug with Connection not caching statements from
prepareStatement() when the statement wasn't a server-side
prepared statement. (Bug#4718: http://bugs.mysql.com/4718)
A.3.10. Changes in MySQL Connector/J 3.1.6 (23 December 2004)
Bugs fixed:
* DBMD.getProcedures() doesn't respect catalog parameter.
(Bug#7026: http://bugs.mysql.com/7026)
* Fixed hang on SocketInputStream.read() with
Statement.setMaxRows() and multiple result sets when driver
has to truncate result set directly, rather than tacking a
LIMIT n on the end of it.
A.3.11. Changes in MySQL Connector/J 3.1.5 (02 December 2004)
Bugs fixed:
* Use 1MB packet for sending file for LOAD DATA LOCAL INFILE if
that is < max_allowed_packet on server.
(Bug#6537: http://bugs.mysql.com/6537)
* SUM() on DECIMAL with server-side prepared statement ignores
scale if zero-padding is needed (this ends up being due to
conversion to DOUBLE by server, which when converted to a
string to parse into BigDecimal, loses all "padding" zeros).
(Bug#6537: http://bugs.mysql.com/6537)
* Use DatabaseMetaData.getIdentifierQuoteString() when building
DBMD queries. (Bug#6537: http://bugs.mysql.com/6537)
* Use our own implementation of buffered input streams to get
around blocking behavior of java.io.BufferedInputStream.
Disable this with useReadAheadInput=false.
(Bug#6399: http://bugs.mysql.com/6399)
* Make auto-deserialization of java.lang.Objects stored in BLOB
columns configurable via autoDeserialize property (defaults to
false). (Bug#6399: http://bugs.mysql.com/6399)
* ResultSetMetaData.getColumnDisplaySize() returns incorrect
values for multi-byte charsets.
(Bug#6399: http://bugs.mysql.com/6399)
* Re-work Field.isOpaqueBinary() to detect CHAR(n) CHARACTER SET
BINARY to support fixed-length binary fields for
ResultSet.getObject(). (Bug#6399: http://bugs.mysql.com/6399)
* Failing to connect to the server when one of the addresses for
the given host name is IPV6 (which the server does not yet
bind on). The driver now loops through all IP addresses for a
given host, and stops on the first one that accepts() a
socket.connect(). (Bug#6348: http://bugs.mysql.com/6348)
* Removed unwanted new Throwable() in ResultSet constructor due
to bad merge (caused a new object instance that was never used
for every result set created). Found while profiling for
Bug#6359: http://bugs.mysql.com/6359.
(Bug#6225: http://bugs.mysql.com/6225)
* ServerSidePreparedStatement allocating short-lived objects
unnecessarily. (Bug#6225: http://bugs.mysql.com/6225)
* Use null-safe-equals for key comparisons in updatable result
sets. (Bug#6225: http://bugs.mysql.com/6225)
* Fixed too-early creation of StringBuffer in
EscapeProcessor.escapeSQL(), also return String when escaping
not needed (to avoid unnecessary object allocations). Found
while profiling for Bug#6359: http://bugs.mysql.com/6359.
(Bug#6225: http://bugs.mysql.com/6225)
* UNSIGNED BIGINT unpacked incorrectly from server-side prepared
statement result sets. (Bug#5729: http://bugs.mysql.com/5729)
* Added experimental configuration property
dontUnpackBinaryResults, which delays unpacking binary result
set values until they're asked for, and only creates object
instances for non-numerical values (it is set to false by
default). For some usecase/jvm combinations, this is
friendlier on the garbage collector.
(Bug#5706: http://bugs.mysql.com/5706)
* Don't throw exceptions for Connection.releaseSavepoint().
(Bug#5706: http://bugs.mysql.com/5706)
* Inefficient detection of pre-existing string instances in
ResultSet.getNativeString().
(Bug#5706: http://bugs.mysql.com/5706)
* Use a per-session Calendar instance by default when decoding
dates from ServerPreparedStatements (set to old, less
performant behavior by setting property
dynamicCalendars=true). (Bug#5706: http://bugs.mysql.com/5706)
* Fixed batched updates with server prepared statements weren't
looking if the types had changed for a given batched set of
parameters compared to the previous set, causing the server to
return the error "Wrong arguments to mysql_stmt_execute()".
(Bug#5235: http://bugs.mysql.com/5235)
* Handle case when string representation of timestamp contains
trailing "." with no numbers following it.
(Bug#5235: http://bugs.mysql.com/5235)
* Server-side prepared statements did not honor
zeroDateTimeBehavior property, and would cause class-cast
exceptions when using ResultSet.getObject(), as the all-zero
string was always returned.
(Bug#5235: http://bugs.mysql.com/5235)
* Fix comparisons made between string constants and dynamic
strings that are converted with either toUpperCase() or
toLowerCase() to use Locale.ENGLISH, as some locales
"override" case rules for English. Also use
StringUtils.indexOfIgnoreCase() instead of
.toUpperCase().indexOf(), avoids creating a very short-lived
transient String instance.
A.3.12. Changes in MySQL Connector/J 3.1.4 (04 September 2004)
Bugs fixed:
* Fixed ServerPreparedStatement to read prepared statement
metadata off the wire, even though it's currently a
placeholder instead of using MysqlIO.clearInputStream() which
didn't work at various times because data wasn't available to
read from the server yet. This fixes sporadic errors users
were having with ServerPreparedStatements throwing
ArrayIndexOutOfBoundExceptions.
(Bug#5032: http://bugs.mysql.com/5032)
* Added three ways to deal with all-zero datetimes when reading
them from a ResultSet: exception (the default), which throws
an SQLException with an SQLState of S1009; convertToNull,
which returns NULL instead of the date; and round, which
rounds the date to the nearest closest value which is
'0001-01-01'. (Bug#5032: http://bugs.mysql.com/5032)
* The driver is more strict about truncation of numerics on
ResultSet.get*(), and will throw an SQLException when
truncation is detected. You can disable this by setting
jdbcCompliantTruncation to false (it is enabled by default, as
this functionality is required for JDBC compliance).
(Bug#5032: http://bugs.mysql.com/5032)
* You can now use URLs in LOAD DATA LOCAL INFILE statements, and
the driver will use Java's built-in handlers for retreiving
the data and sending it to the server. This feature is not
enabled by default, you must set the allowUrlInLocalInfile
connection property to true.
(Bug#5032: http://bugs.mysql.com/5032)
* ResultSet.getObject() doesn't return type Boolean for
pseudo-bit types from prepared statements on 4.1.x (shortcut
for avoiding extra type conversion when using binary-encoded
result sets obscured test in getObject() for "pseudo" bit
type). (Bug#5032: http://bugs.mysql.com/5032)
* Use com.mysql.jdbc.Message's classloader when loading resource
bundle, should fix sporadic issues when the caller's
classloader can't locate the resource bundle.
(Bug#5032: http://bugs.mysql.com/5032)
* ServerPreparedStatements dealing with return of DECIMAL type
don't work. (Bug#5012: http://bugs.mysql.com/5012)
* Track packet sequence numbers if enablePacketDebug=true, and
throw an exception if packets received out-of-order.
(Bug#4689: http://bugs.mysql.com/4689)
* ResultSet.wasNull() does not work for primatives if a previous
null was returned. (Bug#4689: http://bugs.mysql.com/4689)
* Optimized integer number parsing, enable "old" slower integer
parsing using JDK classes via useFastIntParsing=false
property. (Bug#4642: http://bugs.mysql.com/4642)
* Added useOnlyServerErrorMessages property, which causes
message text in exceptions generated by the server to only
contain the text sent by the server (as opposed to the
SQLState's "standard" description, followed by the server's
error message). This property is set to true by default.
(Bug#4642: http://bugs.mysql.com/4642)
* ServerPreparedStatement.execute*() sometimes threw
ArrayIndexOutOfBoundsException when unpacking field metadata.
(Bug#4642: http://bugs.mysql.com/4642)
* Connector/J 3.1.3 beta does not handle integers correctly
(caused by changes to support unsigned reads in
Buffer.readInt() -> Buffer.readShort()).
(Bug#4510: http://bugs.mysql.com/4510)
* Added support in DatabaseMetaData.getTables() and
getTableTypes() for views, which are now available in MySQL
server 5.0.x. (Bug#4510: http://bugs.mysql.com/4510)
* ResultSet.getObject() returns wrong type for strings when
using prepared statements.
(Bug#4482: http://bugs.mysql.com/4482)
* Calling MysqlPooledConnection.close() twice (even though an
application error), caused NPE. Fixed.
(Bug#4482: http://bugs.mysql.com/4482)
A.3.13. Changes in MySQL Connector/J 3.1.3 (07 July 2004)
Bugs fixed:
* Support new time zone variables in MySQL-4.1.3 when
useTimezone=true. (Bug#4311: http://bugs.mysql.com/4311)
* Error in retrieval of mediumint column with prepared
statements and binary protocol.
(Bug#4311: http://bugs.mysql.com/4311)
* Support for unsigned numerics as return types from prepared
statements. This also causes a change in ResultSet.getObject()
for the bigint unsigned type, which used to return BigDecimal
instances, it now returns instances of java.lang.BigInteger.
(Bug#4311: http://bugs.mysql.com/4311)
* Externalized more messages (on-going effort).
(Bug#4119: http://bugs.mysql.com/4119)
* Null bitmask sent for server-side prepared statements was
incorrect. (Bug#4119: http://bugs.mysql.com/4119)
* Added constants for MySQL error numbers (publicly accessible,
see com.mysql.jdbc.MysqlErrorNumbers), and the ability to
generate the mappings of vendor error codes to SQLStates that
the driver uses (for documentation purposes).
(Bug#4119: http://bugs.mysql.com/4119)
* Added packet debuging code (see the enablePacketDebug property
documentation). (Bug#4119: http://bugs.mysql.com/4119)
* Use SQL Standard SQL states by default, unless
useSqlStateCodes property is set to false.
(Bug#4119: http://bugs.mysql.com/4119)
* Mangle output parameter names for CallableStatements so they
will not clash with user variable names.
* Added support for INOUT parameters in CallableStatements.
A.3.14. Changes in MySQL Connector/J 3.1.2 (09 June 2004)
Bugs fixed:
* Don't enable server-side prepared statements for server
version 5.0.0 or 5.0.1, as they aren't compatible with the
'4.1.2+' style that the driver uses (the driver expects
information to come back that isn't there, so it hangs).
(Bug#3804: http://bugs.mysql.com/3804)
* getWarnings() returns SQLWarning instead of DataTruncation.
(Bug#3804: http://bugs.mysql.com/3804)
* getProcedureColumns() doesn't work with wildcards for
procedure name. (Bug#3540: http://bugs.mysql.com/3540)
* getProcedures() does not return any procedures in result set.
(Bug#3539: http://bugs.mysql.com/3539)
* Fixed DatabaseMetaData.getProcedures() when run on MySQL-5.0.0
(output of SHOW PROCEDURE STATUS changed between 5.0.0 and
5.0.1. (Bug#3520: http://bugs.mysql.com/3520)
* Added connectionCollation property to cause driver to issue
set collation_connection=... query on connection init if
default collation for given charset is not appropriate.
(Bug#3520: http://bugs.mysql.com/3520)
* DBMD.getSQLStateType() returns incorrect value.
(Bug#3520: http://bugs.mysql.com/3520)
* Correctly map output parameters to position given in
prepareCall() versus. order implied during
registerOutParameter(). (Bug#3146: http://bugs.mysql.com/3146)
* Cleaned up detection of server properties.
(Bug#3146: http://bugs.mysql.com/3146)
* Correctly detect initial character set for servers >= 4.1.0.
(Bug#3146: http://bugs.mysql.com/3146)
* Support placeholder for parameter metadata for server >=
4.1.2. (Bug#3146: http://bugs.mysql.com/3146)
* Added gatherPerformanceMetrics property, along with properties
to control when/where this info gets logged (see docs for more
info).
* Fixed case when no parameters could cause a
NullPointerException in
CallableStatement.setOutputParameters().
* Enabled callable statement caching via cacheCallableStmts
property.
* Fixed sending of split packets for large queries, enabled nio
ability to send large packets as well.
* Added .toString() functionality to ServerPreparedStatement,
which should help if you're trying to debug a query that is a
prepared statement (it shows SQL as the server would process).
* Added logSlowQueries property, along with
slowQueriesThresholdMillis property to control when a query
should be considered "slow."
* Removed wrapping of exceptions in MysqlIO.changeUser().
* Fixed stored procedure parameter parsing info when size was
specified for a parameter (for example, char(), varchar()).
* ServerPreparedStatements weren't actually de-allocating
server-side resources when .close() was called.
* Fixed case when no output parameters specified for a stored
procedure caused a bogus query to be issued to retrieve out
parameters, leading to a syntax error from the server.
A.3.15. Changes in MySQL Connector/J 3.1.1 (14 February 2004)
Bugs fixed:
* Use DocBook version of docs for shipped versions of drivers.
(Bug#2671: http://bugs.mysql.com/2671)
* NULL fields were not being encoded correctly in all cases in
server-side prepared statements.
(Bug#2671: http://bugs.mysql.com/2671)
* Fixed rare buffer underflow when writing numbers into buffers
for sending prepared statement execution requests.
(Bug#2671: http://bugs.mysql.com/2671)
* Fixed ConnectionProperties that weren't properly exposed via
accessors, cleaned up ConnectionProperties code.
(Bug#2623: http://bugs.mysql.com/2623)
* Class-cast exception when using scrolling result sets and
server-side prepared statements.
(Bug#2623: http://bugs.mysql.com/2623)
* Merged unbuffered input code from 3.0.
(Bug#2623: http://bugs.mysql.com/2623)
* Enabled streaming of result sets from server-side prepared
statements. (Bug#2606: http://bugs.mysql.com/2606)
* Server-side prepared statements were not returning datatype
YEAR correctly. (Bug#2606: http://bugs.mysql.com/2606)
* Fixed charset conversion issue in getTables().
(Bug#2502: http://bugs.mysql.com/2502)
* Implemented multiple result sets returned from a statement or
stored procedure. (Bug#2502: http://bugs.mysql.com/2502)
* Implemented Connection.prepareCall(), and DatabaseMetaData.
getProcedures() and getProcedureColumns().
(Bug#2359: http://bugs.mysql.com/2359)
* Merged prepared statement caching, and .getMetaData() support
from 3.0 branch. (Bug#2359: http://bugs.mysql.com/2359)
* Fixed off-by-1900 error in some cases for years in
TimeUtil.fastDate/TimeCreate() when unpacking results from
server-side prepared statements.
(Bug#2359: http://bugs.mysql.com/2359)
* Reset long binary parameters in ServerPreparedStatement when
clearParameters() is called, by sending COM_RESET_STMT to the
server. (Bug#2359: http://bugs.mysql.com/2359)
* NULL values for numeric types in binary encoded result sets
causing NullPointerExceptions.
(Bug#2359: http://bugs.mysql.com/2359)
* Display where/why a connection was implicitly closed (to aid
debugging). (Bug#1673: http://bugs.mysql.com/1673)
* DatabaseMetaData.getColumns() is not returning correct column
ordinal info for non-'%' column name patterns.
(Bug#1673: http://bugs.mysql.com/1673)
* Fixed NullPointerException in
ServerPreparedStatement.setTimestamp(), as well as year and
month descrepencies in ServerPreparedStatement.setTimestamp(),
setDate(). (Bug#1673: http://bugs.mysql.com/1673)
* Added ability to have multiple database/JVM targets for
compliance and regression/unit tests in build.xml.
(Bug#1673: http://bugs.mysql.com/1673)
* Fixed sending of queries larger than 16M.
(Bug#1673: http://bugs.mysql.com/1673)
* Merged fix of datatype mapping from MySQL type FLOAT to
java.sql.Types.REAL from 3.0 branch.
(Bug#1673: http://bugs.mysql.com/1673)
* Fixed NPE and year/month bad conversions when accessing some
datetime functionality in ServerPreparedStatements and their
resultant result sets. (Bug#1673: http://bugs.mysql.com/1673)
* Added named and indexed input/output parameter support to
CallableStatement. MySQL-5.0.x or newer.
(Bug#1673: http://bugs.mysql.com/1673)
* CommunicationsException implemented, that tries to determine
why communications was lost with a server, and displays
possible reasons when .getMessage() is called.
(Bug#1673: http://bugs.mysql.com/1673)
* Detect collation of column for RSMD.isCaseSensitive().
(Bug#1673: http://bugs.mysql.com/1673)
* Optimized Buffer.readLenByteArray() to return shared empty
byte array when length is 0.
* Fix support for table aliases when checking for all primary
keys in UpdatableResultSet.
* Unpack "unknown" data types from server prepared statements as
Strings.
* Implemented Statement.getWarnings() for MySQL-4.1 and newer
(using SHOW WARNINGS).
* Ensure that warnings are cleared before executing queries on
prepared statements, as-per JDBC spec (now that we support
warnings).
* Correctly initialize datasource properties from JNDI Refs,
including explicitly specified URLs.
* Implemented long data (Blobs, Clobs, InputStreams, Readers)
for server prepared statements.
* Deal with 0-length tokens in EscapeProcessor (caused by
callable statement escape syntax).
* DatabaseMetaData now reports supportsStoredProcedures() for
MySQL versions >= 5.0.0
* Support for mysql_change_user()
(http://dev.mysql.com/doc/refman/4.1/en/mysql-change-user.html
). See the changeUser() method in com.mysql.jdbc.Connection.
* Removed useFastDates connection property.
* Support for NIO. Use useNIO=true on platforms that support
NIO.
* Check for closed connection on delete/update/insert row
operations in UpdatableResultSet.
* Support for transaction savepoints (MySQL >= 4.0.14 or 4.1.1).
* Support "old" profileSql capitalization in
ConnectionProperties. This property is deprecated, you should
use profileSQL if possible.
* Fixed character encoding issues when converting bytes to ASCII
when MySQL doesn't provide the character set, and the JVM is
set to a multi-byte encoding (usually affecting retrieval of
numeric values).
* Centralized setting of result set type and concurrency.
* Fixed bug with UpdatableResultSets not using client-side
prepared statements.
* Default result set type changed to TYPE_FORWARD_ONLY (JDBC
compliance).
* Fixed IllegalAccessError to Calendar.getTimeInMillis() in
DateTimeValue (for JDK < 1.4).
* Allow contents of PreparedStatement.setBlob() to be retained
between calls to .execute*().
* Fixed stack overflow in Connection.prepareCall() (bad merge).
* Refactored how connection properties are set and exposed as
DriverPropertyInfo as well as Connection and DataSource
properties.
* Reduced number of methods called in average query to be more
efficient.
* Prepared Statements will be re-prepared on auto-reconnect. Any
errors encountered are postponed until first attempt to
re-execute the re-prepared statement.
A.3.16. Changes in MySQL Connector/J 3.1.0 (18 February 2003)
Bugs fixed:
* Added useServerPrepStmts property (default false). The driver
will use server-side prepared statements when the server
version supports them (4.1 and newer) when this property is
set to true. It is currently set to false by default until all
bind/fetch functionality has been implemented. Currently only
DML prepared statements are implemented for 4.1 server-side
prepared statements.
* Added requireSSL property.
* Track open Statements, close all when Connection.close() is
called (JDBC compliance).
A.4. Changes in MySQL Connector/J 3.0.x
A.4.1. Changes in MySQL Connector/J 3.0.17 (23 June 2005)
Bugs fixed:
* Workaround for server Bug#9098: http://bugs.mysql.com/9098:
Default values of CURRENT_* for DATE, TIME, DATETIME, and
TIMESTAMP columns can't be distinguished from string values,
so UpdatableResultSet.moveToInsertRow() generates bad SQL for
inserting default values.
(Bug#8812: http://bugs.mysql.com/8812)
* NON_UNIQUE column from DBMD.getIndexInfo() returned inverted
value. (Bug#8812: http://bugs.mysql.com/8812)
* EUCKR charset is sent as SET NAMES euc_kr which MySQL-4.1 and
newer doesn't understand.
(Bug#8629: http://bugs.mysql.com/8629)
* Added support for the EUC_JP_Solaris character encoding, which
maps to a MySQL encoding of eucjpms (backported from 3.1
branch). This only works on servers that support eucjpms,
namely 5.0.3 or later. (Bug#8629: http://bugs.mysql.com/8629)
* Use hex escapes for PreparedStatement.setBytes() for
double-byte charsets including "aliases" Windows-31J, CP934,
MS932. (Bug#8629: http://bugs.mysql.com/8629)
* DatabaseMetaData.supportsSelectForUpdate() returns correct
value based on server version.
(Bug#8629: http://bugs.mysql.com/8629)
* Which requires hex escaping of binary data when using
multi-byte charsets with prepared statements.
(Bug#8064: http://bugs.mysql.com/8064)
* Fixed duplicated code in configureClientCharset() that
prevented useOldUTF8Behavior=true from working properly.
(Bug#7952: http://bugs.mysql.com/7952)
* Backported SQLState codes mapping from Connector/J 3.1, enable
with useSqlStateCodes=true as a connection property, it
defaults to false in this release, so that we don't break
legacy applications (it defaults to true starting with
Connector/J 3.1). (Bug#7686: http://bugs.mysql.com/7686)
* Timestamp key column data needed _binary stripped for
UpdatableResultSet.refreshRow().
(Bug#7686: http://bugs.mysql.com/7686)
* MS932, SHIFT_JIS, and Windows_31J not recognized as aliases
for sjis. (Bug#7607: http://bugs.mysql.com/7607)
* Handle streaming result sets with more than 2 billion rows
properly by fixing wraparound of row number counter.
(Bug#7601: http://bugs.mysql.com/7601)
* PreparedStatement.fixDecimalExponent() adding extra +, making
number unparseable by MySQL server.
(Bug#7601: http://bugs.mysql.com/7601)
* Escape sequence {fn convert(..., type)} now supports
ODBC-style types that are prepended by SQL_.
(Bug#7601: http://bugs.mysql.com/7601)
* Statements created from a pooled connection were returning
physical connection instead of logical connection when
getConnection() was called.
(Bug#7316: http://bugs.mysql.com/7316)
* Support new protocol type MYSQL_TYPE_VARCHAR.
(Bug#7081: http://bugs.mysql.com/7081)
* Added useOldUTF8Behavior' configuration property, which causes
JDBC driver to act like it did with MySQL-4.0.x and earlier
when the character encoding is utf-8 when connected to
MySQL-4.1 or newer. (Bug#7081: http://bugs.mysql.com/7081)
* DatabaseMetaData.getIndexInfo() ignored unique parameter.
(Bug#7081: http://bugs.mysql.com/7081)
* PreparedStatement.fixDecimalExponent() adding extra +, making
number unparseable by MySQL server.
(Bug#7061: http://bugs.mysql.com/7061)
* PreparedStatements don't encode Big5 (and other multi-byte)
character sets correctly in static SQL strings.
(Bug#7033: http://bugs.mysql.com/7033)
* Connections starting up failed-over (due to down master) never
retry master. (Bug#6966: http://bugs.mysql.com/6966)
* Adding CP943 to aliases for sjis.
(Bug#6549: http://bugs.mysql.com/6549,
Bug#7607: http://bugs.mysql.com/7607)
* Timestamp/Time conversion goes in the wrong "direction" when
useTimeZone=true and server time zone differs from client time
zone. (Bug#5874: http://bugs.mysql.com/5874)
A.4.2. Changes in MySQL Connector/J 3.0.16 (15 November 2004)
Bugs fixed:
* Made TINYINT(1) -> BIT/Boolean conversion configurable via
tinyInt1isBit property (default true to be JDBC compliant out
of the box). (Bug#5664: http://bugs.mysql.com/5664)
* Off-by-one bug in Buffer.readString(string).
(Bug#5664: http://bugs.mysql.com/5664)
* ResultSet.updateByte() when on insert row throws
ArrayOutOfBoundsException.
(Bug#5664: http://bugs.mysql.com/5664)
* Fixed regression where useUnbufferedInput was defaulting to
false. (Bug#5664: http://bugs.mysql.com/5664)
* ResultSet.getTimestamp() on a column with TIME in it fails.
(Bug#5664: http://bugs.mysql.com/5664)
* Fixed DatabaseMetaData.getTypes() returning incorrect (this
is, non-negative) scale for the NUMERIC type.
(Bug#5664: http://bugs.mysql.com/5664)
* Only set character_set_results during connection establishment
if server version >= 4.1.1.
(Bug#5664: http://bugs.mysql.com/5664)
* Fixed ResultSetMetaData.isReadOnly() to detect non-writable
columns when connected to MySQL-4.1 or newer, based on
existence of "original" table and column names.
* Re-issue character set configuration commands when re-using
pooled connections and/or Connection.changeUser() when
connected to MySQL-4.1 or newer.
A.4.3. Changes in MySQL Connector/J 3.0.15 (04 September 2004)
Bugs fixed:
* ResultSet.getMetaData() should not return incorrectly
initialized metadata if the result set has been closed, but
should instead throw an SQLException. Also fixed for getRow()
and getWarnings() and traversal methods by calling
checkClosed() before operating on instance-level fields that
are nullified during .close().
(Bug#5069: http://bugs.mysql.com/5069)
* Use _binary introducer for PreparedStatement.setBytes() and
set*Stream() when connected to MySQL-4.1.x or newer to avoid
misinterpretation during character conversion.
(Bug#5069: http://bugs.mysql.com/5069)
* Parse new time zone variables from 4.1.x servers.
(Bug#5069: http://bugs.mysql.com/5069)
* ResultSet should release Field[] instance in .close().
(Bug#5022: http://bugs.mysql.com/5022)
* RSMD.getPrecision() returning 0 for non-numeric types (should
return max length in chars for non-binary types, max length in
bytes for binary types). This fix also fixes mapping of
RSMD.getColumnType() and RSMD.getColumnTypeName() for the BLOB
types based on the length sent from the server (the server
doesn't distinguish between TINYBLOB, BLOB, MEDIUMBLOB or
LONGBLOB at the network protocol level).
(Bug#4880: http://bugs.mysql.com/4880)
* "Production" is now "GA" (General Availability) in naming
scheme of distributions.
(Bug#4860: http://bugs.mysql.com/4860,
Bug#4138: http://bugs.mysql.com/4138)
* DBMD.getColumns() returns incorrect JDBC type for unsigned
columns. This affects type mappings for all numeric types in
the RSMD.getColumnType() and RSMD.getColumnTypeNames() methods
as well, to ensure that "like" types from DBMD.getColumns()
match up with what RSMD.getColumnType() and
getColumnTypeNames() return.
(Bug#4860: http://bugs.mysql.com/4860,
Bug#4138: http://bugs.mysql.com/4138)
* Calling .close() twice on a PooledConnection causes NPE.
(Bug#4808: http://bugs.mysql.com/4808)
* DOUBLE mapped twice in DBMD.getTypeInfo().
(Bug#4742: http://bugs.mysql.com/4742)
* Added FLOSS license exemption.
(Bug#4742: http://bugs.mysql.com/4742)
* Removed redundant calls to checkRowPos() in ResultSet.
(Bug#4334: http://bugs.mysql.com/4334)
* Failover for autoReconnect not using port numbers for any
hosts, and not retrying all hosts.
Warning
This required a change to the SocketFactory connect() method
signature, which is now public Socket connect(String host, int
portNumber, Properties props); therefore, any third-party
socket factories will have to be changed to support this
signature.
(Bug#4334: http://bugs.mysql.com/4334)
* Logical connections created by MysqlConnectionPoolDataSource
will now issue a rollback() when they are closed and sent back
to the pool. If your application server/connection pool
already does this for you, you can set the
rollbackOnPooledClose property to false to avoid the overhead
of an extra rollback(). (Bug#4334: http://bugs.mysql.com/4334)
* StringUtils.escapeEasternUnicodeByteStream was still broken
for GBK. (Bug#4010: http://bugs.mysql.com/4010)
A.4.4. Changes in MySQL Connector/J 3.0.14 (28 May 2004)
Bugs fixed:
* Fixed URL parsing error.
A.4.5. Changes in MySQL Connector/J 3.0.13 (27 May 2004)
Bugs fixed:
* No Database Selected when using MysqlConnectionPoolDataSource.
(Bug#3920: http://bugs.mysql.com/3920)
* PreparedStatement.getGeneratedKeys() method returns only 1
result for batched insertions.
(Bug#3873: http://bugs.mysql.com/3873)
* Using a MySQLDatasource without server name fails.
(Bug#3848: http://bugs.mysql.com/3848)
A.4.6. Changes in MySQL Connector/J 3.0.12 (18 May 2004)
Bugs fixed:
* Inconsistent reporting of data type. The server still doesn't
return all types for *BLOBs *TEXT correctly, so the driver
won't return those correctly.
(Bug#3570: http://bugs.mysql.com/3570)
* UpdatableResultSet not picking up default values for
moveToInsertRow(). (Bug#3557: http://bugs.mysql.com/3557)
* Not specifying database in URL caused MalformedURL exception.
(Bug#3554: http://bugs.mysql.com/3554)
* Auto-convert MySQL encoding names to Java encoding names if
used for characterEncoding property.
(Bug#3554: http://bugs.mysql.com/3554)
* Use junit.textui.TestRunner for all unit tests (to allow them
to be run from the command line outside of Ant or Eclipse).
(Bug#3554: http://bugs.mysql.com/3554)
* Added encoding names that are recognized on some JVMs to fix
case where they were reverse-mapped to MySQL encoding names
incorrectly. (Bug#3554: http://bugs.mysql.com/3554)
* Made StringRegressionTest 4.1-unicode aware.
(Bug#3520: http://bugs.mysql.com/3520)
* Fixed regression in PreparedStatement.setString() and eastern
character encodings. (Bug#3520: http://bugs.mysql.com/3520)
* DBMD.getSQLStateType() returns incorrect value.
(Bug#3520: http://bugs.mysql.com/3520)
* Renamed StringUtils.escapeSJISByteStream() to more appropriate
escapeEasternUnicodeByteStream().
(Bug#3511: http://bugs.mysql.com/3511)
* StringUtils.escapeSJISByteStream() not covering all eastern
double-byte charsets correctly.
(Bug#3511: http://bugs.mysql.com/3511)
* Return creating statement for ResultSets created by
getGeneratedKeys(). (Bug#2957: http://bugs.mysql.com/2957)
* Use SET character_set_results during initialization to allow
any charset to be returned to the driver for result sets.
(Bug#2670: http://bugs.mysql.com/2670)
* Don't truncate BLOB or CLOB values when using setBytes()
and/or setBinary/CharacterStream(). .
(Bug#2670: http://bugs.mysql.com/2670)
* Dynamically configure character set mappings for field-level
character sets on MySQL-4.1.0 and newer using SHOW COLLATION
when connecting. (Bug#2670: http://bugs.mysql.com/2670)
* Map binary character set to US-ASCII to support DATETIME
charset recognition for servers >= 4.1.2.
(Bug#2670: http://bugs.mysql.com/2670)
* Use charsetnr returned during connect to encode queries before
issuing SET NAMES on MySQL >= 4.1.0.
(Bug#2670: http://bugs.mysql.com/2670)
* Add helper methods to ResultSetMetaData
(getColumnCharacterEncoding() and getColumnCharacterSet()) to
allow end-users to see what charset the driver thinks it
should be using for the column.
(Bug#2670: http://bugs.mysql.com/2670)
* Only set character_set_results for MySQL >= 4.1.0.
(Bug#2670: http://bugs.mysql.com/2670)
* Allow url parameter for MysqlDataSource and
MysqlConnectionPool DataSource so that passing of other
properties is possible from inside appservers.
* Don't escape SJIS/GBK/BIG5 when using MySQL-4.1 or newer.
* Backport documentation tooling from 3.1 branch.
* Added failOverReadOnly property, to allow end-user to
configure state of connection (read-only/writable) when failed
over.
* Allow java.util.Date to be sent in as parameter to
PreparedStatement.setObject(), converting it to a Timestamp to
maintain full precision. .
(Bug#103: http://bugs.mysql.com/103)
* Add unsigned attribute to DatabaseMetaData.getColumns() output
in the TYPE_NAME column.
* Map duplicate key and foreign key errors to SQLState of 23000.
* Backported "change user" and "reset server state"
functionality from 3.1 branch, to allow clients of
MysqlConnectionPoolDataSource to reset server state on
getConnection() on a pooled connection.
A.4.7. Changes in MySQL Connector/J 3.0.11 (19 February 2004)
Bugs fixed:
* Return java.lang.Double for FLOAT type from
ResultSetMetaData.getColumnClassName().
(Bug#2855: http://bugs.mysql.com/2855)
* Return [B instead of java.lang.Object for BINARY, VARBINARY
and LONGVARBINARY types from
ResultSetMetaData.getColumnClassName() (JDBC compliance).
(Bug#2855: http://bugs.mysql.com/2855)
* Issue connection events on all instances created from a
ConnectionPoolDataSource.
(Bug#2855: http://bugs.mysql.com/2855)
* Return java.lang.Integer for TINYINT and SMALLINT types from
ResultSetMetaData.getColumnClassName().
(Bug#2852: http://bugs.mysql.com/2852)
* Added useUnbufferedInput parameter, and now use it by default
(due to JVM issue
http://developer.java.sun.com/developer/bugParade/bugs/4401235
.html) (Bug#2578: http://bugs.mysql.com/2578)
* Fixed failover always going to last host in list.
(Bug#2578: http://bugs.mysql.com/2578)
* Detect on/off or 1, 2, 3 form of lower_case_table_names value
on server. (Bug#2578: http://bugs.mysql.com/2578)
* AutoReconnect time was growing faster than exponentially.
(Bug#2447: http://bugs.mysql.com/2447)
* Trigger a SET NAMES utf8 when encoding is forced to utf8 or
utf-8 via the characterEncoding property. Previously, only the
Java-style encoding name of utf-8 would trigger this.
A.4.8. Changes in MySQL Connector/J 3.0.10 (13 January 2004)
Bugs fixed:
* Enable caching of the parsing stage of prepared statements via
the cachePrepStmts, prepStmtCacheSize, and
prepStmtCacheSqlLimit properties (disabled by default).
(Bug#2006: http://bugs.mysql.com/2006)
* Fixed security exception when used in Applets (applets can't
read the system property file.encoding which is needed for
LOAD DATA LOCAL INFILE).
(Bug#2006: http://bugs.mysql.com/2006)
* Speed up parsing of PreparedStatements, try to use one-pass
whenever possible. (Bug#2006: http://bugs.mysql.com/2006)
* Fixed exception Unknown character set 'danish' on connect with
JDK-1.4.0 (Bug#2006: http://bugs.mysql.com/2006)
* Fixed mappings in SQLError to report deadlocks with SQLStates
of 41000. (Bug#2006: http://bugs.mysql.com/2006)
* Removed static synchronization bottleneck from instance
factory method of SingleByteCharsetConverter.
(Bug#2006: http://bugs.mysql.com/2006)
* Removed static synchronization bottleneck from
PreparedStatement.setTimestamp().
(Bug#2006: http://bugs.mysql.com/2006)
* ResultSet.findColumn() should use first matching column name
when there are duplicate column names in SELECT query
(JDBC-compliance). (Bug#2006: http://bugs.mysql.com/2006)
* maxRows property would affect internal statements, so check it
for all statement creation internal to the driver, and set to
0 when it is not. (Bug#2006: http://bugs.mysql.com/2006)
* Use constants for SQLStates.
(Bug#2006: http://bugs.mysql.com/2006)
* Map charset ko18_ru to ko18r when connected to MySQL-4.1.0 or
newer. (Bug#2006: http://bugs.mysql.com/2006)
* Ensure that Buffer.writeString() saves room for the \0.
(Bug#2006: http://bugs.mysql.com/2006)
* ArrayIndexOutOfBounds when parameter number == number of
parameters + 1. (Bug#1958: http://bugs.mysql.com/1958)
* Connection property maxRows not honored.
(Bug#1933: http://bugs.mysql.com/1933)
* Statements being created too many times in
DBMD.extractForeignKeyFromCreateTable().
(Bug#1925: http://bugs.mysql.com/1925)
* Support escape sequence {fn convert ... }.
(Bug#1914: http://bugs.mysql.com/1914)
* Implement ResultSet.updateClob().
(Bug#1913: http://bugs.mysql.com/1913)
* Autoreconnect code didn't set catalog upon reconnect if it had
been changed. (Bug#1913: http://bugs.mysql.com/1913)
* ResultSet.getObject() on TINYINT and SMALLINT columns should
return Java type Integer.
(Bug#1913: http://bugs.mysql.com/1913)
* Added more descriptive error message Server Configuration
Denies Access to DataSource, as well as retrieval of message
from server. (Bug#1913: http://bugs.mysql.com/1913)
* ResultSetMetaData.isCaseSensitive() returned wrong value for
CHAR/VARCHAR columns. (Bug#1913: http://bugs.mysql.com/1913)
* Added alwaysClearStream connection property, which causes the
driver to always empty any remaining data on the input stream
before each query. (Bug#1913: http://bugs.mysql.com/1913)
* DatabaseMetaData.getSystemFunction() returning bad function
VResultsSion. (Bug#1775: http://bugs.mysql.com/1775)
* Foreign Keys column sequence is not consistent in
DatabaseMetaData.getImported/Exported/CrossReference().
(Bug#1731: http://bugs.mysql.com/1731)
* Fix for ArrayIndexOutOfBounds exception when using
Statement.setMaxRows(). (Bug#1695: http://bugs.mysql.com/1695)
* Subsequent call to ResultSet.updateFoo() causes NPE if result
set is not updatable. (Bug#1630: http://bugs.mysql.com/1630)
* Fix for 4.1.1-style authentication with no password.
(Bug#1630: http://bugs.mysql.com/1630)
* Cross-database updatable result sets are not checked for
updatability correctly. (Bug#1592: http://bugs.mysql.com/1592)
* DatabaseMetaData.getColumns() should return Types.LONGVARCHAR
for MySQL LONGTEXT type.
(Bug#1592: http://bugs.mysql.com/1592)
* Fixed regression of Statement.getGeneratedKeys() and REPLACE
statements. (Bug#1576: http://bugs.mysql.com/1576)
* Barge blobs and split packets not being read correctly.
(Bug#1576: http://bugs.mysql.com/1576)
* Backported fix for aliased tables and UpdatableResultSets in
checkUpdatability() method from 3.1 branch.
(Bug#1534: http://bugs.mysql.com/1534)
* "Friendlier" exception message for PacketTooLargeException.
(Bug#1534: http://bugs.mysql.com/1534)
* Don't count quoted IDs when inside a 'string' in
PreparedStatement parsing.
(Bug#1511: http://bugs.mysql.com/1511)
A.4.9. Changes in MySQL Connector/J 3.0.9 (07 October 2003)
Bugs fixed:
* ResultSet.get/setString mashing char 127.
(Bug#1247: http://bugs.mysql.com/1247)
* Added property to "clobber" streaming results, by setting the
clobberStreamingResults property to true (the default is
false). This will cause a "streaming" ResultSet to be
automatically closed, and any oustanding data still streaming
from the server to be discarded if another query is executed
before all the data has been read from the server.
(Bug#1247: http://bugs.mysql.com/1247)
* Added com.mysql.jdbc.util.BaseBugReport to help creation of
testcases for bug reports.
(Bug#1247: http://bugs.mysql.com/1247)
* Backported authentication changes for 4.1.1 and newer from 3.1
branch. (Bug#1247: http://bugs.mysql.com/1247)
* Made databaseName, portNumber, and serverName optional
parameters for MysqlDataSourceFactory.
(Bug#1246: http://bugs.mysql.com/1246)
* Optimized CLOB.setChracterStream().
(Bug#1131: http://bugs.mysql.com/1131)
* Fixed CLOB.truncate(). (Bug#1130: http://bugs.mysql.com/1130)
* Fixed deadlock issue with Statement.setMaxRows().
(Bug#1099: http://bugs.mysql.com/1099)
* DatabaseMetaData.getColumns() getting confused about the
keyword "set" in character columns.
(Bug#1099: http://bugs.mysql.com/1099)
* Clip +/- INF (to smallest and largest representative values
for the type in MySQL) and NaN (to 0) for
setDouble/setFloat(), and issue a warning on the statement
when the server does not support +/- INF or NaN.
(Bug#884: http://bugs.mysql.com/884)
* Don't fire connection closed events when closing pooled
connections, or on PooledConnection.getConnection() with
already open connections. (Bug#884: http://bugs.mysql.com/884)
* Double-escaping of '\' when charset is SJIS or GBK and '\'
appears in non-escaped input.
(Bug#879: http://bugs.mysql.com/879)
* When emptying input stream of unused rows for "streaming"
result sets, have the current thread yield() every 100 rows in
order to not monopolize CPU time.
(Bug#879: http://bugs.mysql.com/879)
* Issue exception on ResultSet.getXXX() on empty result set
(wasn't caught in some cases).
(Bug#848: http://bugs.mysql.com/848)
* Don't hide messages from exceptions thrown in I/O layers.
(Bug#848: http://bugs.mysql.com/848)
* Fixed regression in large split-packet handling.
(Bug#848: http://bugs.mysql.com/848)
* Better diagnostic error messages in exceptions for "streaming"
result sets. (Bug#848: http://bugs.mysql.com/848)
* Don't change timestamp TZ twice if useTimezone==true.
(Bug#774: http://bugs.mysql.com/774)
* Don't wrap SQLExceptions in RowDataDynamic.
(Bug#688: http://bugs.mysql.com/688)
* Don't try and reset isolation level on reconnect if MySQL
doesn't support them. (Bug#688: http://bugs.mysql.com/688)
* The insertRow in an UpdatableResultSet is now loaded with the
default column values when moveToInsertRow() is called.
(Bug#688: http://bugs.mysql.com/688)
* DatabaseMetaData.getColumns() wasn't returning NULL for
default values that are specified as NULL.
(Bug#688: http://bugs.mysql.com/688)
* Change default statement type/concurrency to TYPE_FORWARD_ONLY
and CONCUR_READ_ONLY (spec compliance).
(Bug#688: http://bugs.mysql.com/688)
* Fix UpdatableResultSet to return values for getXXX() when on
insert row. (Bug#675: http://bugs.mysql.com/675)
* Support InnoDB contraint names when extracting foreign key
information in DatabaseMetaData (implementing ideas from
Parwinder Sekhon). (Bug#664: http://bugs.mysql.com/664,
Bug#517: http://bugs.mysql.com/517)
* Backported 4.1 protocol changes from 3.1 branch (server-side
SQL states, new field information, larger client capability
flags, connect-with-database, and so forth).
(Bug#664: http://bugs.mysql.com/664,
Bug#517: http://bugs.mysql.com/517)
* refreshRow didn't work when primary key values contained
values that needed to be escaped (they ended up being doubly
escaped). (Bug#661: http://bugs.mysql.com/661)
* Fixed ResultSet.previous() behavior to move current position
to before result set when on first row of result set.
(Bug#496: http://bugs.mysql.com/496)
* Fixed Statement and PreparedStatement issuing bogus queries
when setMaxRows() had been used and a LIMIT clause was present
in the query. (Bug#496: http://bugs.mysql.com/496)
* Faster date handling code in ResultSet and PreparedStatement
(no longer uses Date methods that synchronize on static
calendars).
* Fixed test for end of buffer in Buffer.readString().
A.4.10. Changes in MySQL Connector/J 3.0.8 (23 May 2003)
Bugs fixed:
* Fixed SJIS encoding bug, thanks to Naoto Sato.
(Bug#378: http://bugs.mysql.com/378)
* Fix problem detecting server character set in some cases.
(Bug#378: http://bugs.mysql.com/378)
* Allow multiple calls to Statement.close().
(Bug#378: http://bugs.mysql.com/378)
* Return correct number of generated keys when using REPLACE
statements. (Bug#378: http://bugs.mysql.com/378)
* Unicode character 0xFFFF in a string would cause the driver to
throw an ArrayOutOfBoundsException. .
(Bug#378: http://bugs.mysql.com/378)
* Fix row data decoding error when using very large packets.
(Bug#378: http://bugs.mysql.com/378)
* Optimized row data decoding.
(Bug#378: http://bugs.mysql.com/378)
* Issue exception when operating on an already closed prepared
statement. (Bug#378: http://bugs.mysql.com/378)
* Optimized usage of EscapeProcessor.
(Bug#378: http://bugs.mysql.com/378)
* Use JVM charset with filenames and LOAD DATA [LOCAL] INFILE.
* Fix infinite loop with Connection.cleanup().
* Changed Ant target compile-core to compile-driver, and made
testsuite compilation a separate target.
* Fixed result set not getting set for
Statement.executeUpdate(), which affected getGeneratedKeys()
and getUpdateCount() in some cases.
* Return list of generated keys when using multi-value INSERTS
with Statement.getGeneratedKeys().
* Allow bogus URLs in Driver.getPropertyInfo().
A.4.11. Changes in MySQL Connector/J 3.0.7 (08 April 2003)
Bugs fixed:
* Fixed charset issues with database metadata (charset was not
getting set correctly).
* You can now toggle profiling on/off using
Connection.setProfileSql(boolean).
* 4.1 Column Metadata fixes.
* Fixed MysqlPooledConnection.close() calling wrong event type.
* Fixed StringIndexOutOfBoundsException in
PreparedStatement.setClob().
* IOExceptions during a transaction now cause the Connection to
be closed.
* Remove synchronization from Driver.connect() and
Driver.acceptsUrl().
* Fixed missing conversion for YEAR type in
ResultSetMetaData.getColumnTypeName().
* Updatable ResultSets can now be created for aliased
tables/columns when connected to MySQL-4.1 or newer.
* Fixed LOAD DATA LOCAL INFILE bug when file >
max_allowed_packet.
* Don't pick up indexes that start with pri as primary keys for
DBMD.getPrimaryKeys().
* Ensure that packet size from alignPacketSize() does not exceed
max_allowed_packet (JVM bug)
* Don't reset Connection.isReadOnly() when autoReconnecting.
* Fixed escaping of 0x5c ('\') character for GBK and Big5
charsets.
* Fixed ResultSet.getTimestamp() when underlying field is of
type DATE.
* Throw SQLExceptions when trying to do operations on a
forcefully closed Connection (that is, when a communication
link failure occurs).
A.4.12. Changes in MySQL Connector/J 3.0.6 (18 February 2003)
Bugs fixed:
* Backported 4.1 charset field info changes from Connector/J
3.1.
* Fixed Statement.setMaxRows() to stop sending LIMIT type
queries when not needed (performance).
* Fixed DBMD.getTypeInfo() and DBMD.getColumns() returning
different value for precision in TEXT and BLOB types.
* Fixed SQLExceptions getting swallowed on initial connect.
* Fixed ResultSetMetaData to return "" when catalog not known.
Fixes NullPointerExceptions with Sun's CachedRowSet.
* Allow ignoring of warning for "non transactional tables"
during rollback (compliance/usability) by setting
ignoreNonTxTables property to true.
* Clean up Statement query/method mismatch tests (that is,
INSERT not allowed with .executeQuery()).
* Fixed ResultSetMetaData.isWritable() to return correct value.
* More checks added in ResultSet traversal method to catch when
in closed state.
* Implemented Blob.setBytes(). You still need to pass the
resultant Blob back into an updatable ResultSet or
PreparedStatement to persist the changes, because MySQL does
not support "locators".
* Add "window" of different NULL sorting behavior to
DBMD.nullsAreSortedAtStart (4.0.2 to 4.0.10, true; otherwise,
no).
A.4.13. Changes in MySQL Connector/J 3.0.5 (22 January 2003)
Bugs fixed:
* Fixed ResultSet.isBeforeFirst() for empty result sets.
* Added missing LONGTEXT type to DBMD.getColumns().
* Implemented an empty TypeMap for Connection.getTypeMap() so
that some third-party apps work with MySQL (IBM WebSphere 5.0
Connection pool).
* Added update options for foreign key metadata.
* Fixed Buffer.fastSkipLenString() causing ArrayIndexOutOfBounds
exceptions with some queries when unpacking fields.
* Quote table names in DatabaseMetaData.getColumns(),
getPrimaryKeys(), getIndexInfo(), getBestRowIdentifier().
* Retrieve TX_ISOLATION from database for
Connection.getTransactionIsolation() when the MySQL version
supports it, instead of an instance variable.
* Greatly reduce memory required for setBinaryStream() in
PreparedStatements.
A.4.14. Changes in MySQL Connector/J 3.0.4 (06 January 2003)
Bugs fixed:
* Streamlined character conversion and byte[] handling in
PreparedStatements for setByte().
* Fixed PreparedStatement.executeBatch() parameter overwriting.
* Added quoted identifiers to database names for
Connection.setCatalog.
* Added support for 4.0.8-style large packets.
* Reduce memory footprint of PreparedStatements by sharing
outbound packet with MysqlIO.
* Added strictUpdates property to allow control of amount of
checking for "correctness" of updatable result sets. Set this
to false if you want faster updatable result sets and you know
that you create them from SELECT statements on tables with
primary keys and that you have selected all primary keys in
your query.
* Added support for quoted identifiers in PreparedStatement
parser.
A.4.15. Changes in MySQL Connector/J 3.0.3 (17 December 2002)
Bugs fixed:
* Allow user to alter behavior of Statement/
PreparedStatement.executeBatch() via continueBatchOnError
property (defaults to true).
* More robust escape tokenizer: Recognize -- comments, and allow
nested escape sequences (see testsuite.EscapeProcessingTest).
* Fixed Buffer.isLastDataPacket() for 4.1 and newer servers.
* NamedPipeSocketFactory now works (only intended for Windows),
see README for instructions.
* Changed charsToByte in SingleByteCharConverter to be
non-static.
* Use non-aliased table/column names and database names to fully
qualify tables and columns in UpdatableResultSet (requires
MySQL-4.1 or newer).
* LOAD DATA LOCAL INFILE ... now works, if your server is
configured to allow it. Can be turned off with the
allowLoadLocalInfile property (see the README).
* Implemented Connection.nativeSQL().
* Fixed ResultSetMetaData.getColumnTypeName() returning BLOB for
TEXT and TEXT for BLOB types.
* Fixed charset handling in Fields.java.
* Because of above, implemented
ResultSetMetaData.isAutoIncrement() to use
Field.isAutoIncrement().
* Substitute '?' for unknown character conversions in
single-byte character sets instead of '\0'.
* Added CLIENT_LONG_FLAG to be able to get more column flags
(isAutoIncrement() being the most important).
* Honor lower_case_table_names when enabled in the server when
doing table name comparisons in DatabaseMetaData methods.
* DBMD.getImported/ExportedKeys() now handles multiple foreign
keys per table.
* More robust implementation of updatable result sets. Checks
that all primary keys of the table have been selected.
* Some MySQL-4.1 protocol support (extended field info from
selects).
* Check for connection closed in more Connection methods
(createStatement, prepareStatement, setTransactionIsolation,
setAutoCommit).
* Fixed ResultSetMetaData.getPrecision() returning incorrect
values for some floating-point types.
* Changed SingleByteCharConverter to use lazy initialization of
each converter.
A.4.16. Changes in MySQL Connector/J 3.0.2 (08 November 2002)
Bugs fixed:
* Implemented Clob.setString().
* Added com.mysql.jdbc.MiniAdmin class, which allows you to send
shutdown command to MySQL server. This is intended to be used
when "embedding" Java and MySQL server together in an end-user
application.
* Added SSL support. See README for information on how to use
it.
* All DBMD result set columns describing schemas now return NULL
to be more compliant with the behavior of other JDBC drivers
for other database systems (MySQL does not support schemas).
* Use SHOW CREATE TABLE when possible for determining foreign
key information for DatabaseMetaData. Also allows cascade
options for DELETE information to be returned.
* Implemented Clob.setCharacterStream().
* Failover and autoReconnect work only when the connection is in
an autoCommit(false) state, in order to stay transaction-safe.
* Fixed DBMD.supportsResultSetConcurrency() so that it returns
true for ResultSet.TYPE_SCROLL_INSENSITIVE and
ResultSet.CONCUR_READ_ONLY or ResultSet.CONCUR_UPDATABLE.
* Implemented Clob.setAsciiStream().
* Removed duplicate code from UpdatableResultSet (it can be
inherited from ResultSet, the extra code for each method to
handle updatability I thought might someday be necessary has
not been needed).
* Fixed UnsupportedEncodingException thrown when "forcing" a
character encoding via properties.
* Fixed incorrect conversion in ResultSet.getLong().
* Implemented ResultSet.updateBlob().
* Removed some not-needed temporary object creation by smarter
use of Strings in EscapeProcessor, Connection and
DatabaseMetaData classes.
* Escape 0x5c character in strings for the SJIS charset.
* PreparedStatement now honors stream lengths in
setBinary/Ascii/Character Stream() unless you set the
connection property useStreamLengthsInPrepStmts to false.
* Fixed issue with updatable result sets and PreparedStatements
not working.
* Fixed start position off-by-1 error in Clob.getSubString().
* Added connectTimeout parameter that allows users of JDK-1.4
and newer to specify a maximum time to wait to establish a
connection.
* Fixed various non-ASCII character encoding issues.
* Fixed ResultSet.isLast() for empty result sets (should return
false).
* Added driver property useHostsInPrivileges. Defaults to true.
Affects whether or not @hostname will be used in
DBMD.getColumn/TablePrivileges.
* Fixed ResultSet.setFetchDirection(FETCH_UNKNOWN).
* Added queriesBeforeRetryMaster property that specifies how
many queries to issue when failed over before attempting to
reconnect to the master (defaults to 50).
* Fixed issue when calling Statement.setFetchSize() when using
arbitrary values.
* Properly restore connection properties when autoReconnecting
or failing-over, including autoCommit state, and isolation
level.
* Implemented Clob.truncate().
A.4.17. Changes in MySQL Connector/J 3.0.1 (21 September 2002)
Bugs fixed:
* Charsets now automatically detected. Optimized code for
single-byte character set conversion.
* Fixed ResultSetMetaData.isSigned() for TINYINT and BIGINT.
* Fixed RowDataStatic.getAt() off-by-one bug.
* Fixed ResultSet.getRow() off-by-one bug.
* Massive code clean-up to follow Java coding conventions (the
time had come).
* Implemented ResultSet.getCharacterStream().
* Added limited Clob functionality (ResultSet.getClob(),
PreparedStatemtent.setClob(),
PreparedStatement.setObject(Clob).
* Connection.isClosed() no longer "pings" the server.
* Connection.close() issues rollback() when getAutoCommit() is
false.
* Added socketTimeout parameter to URL.
* Added LOCAL TEMPORARY to table types in
DatabaseMetaData.getTableTypes().
* Added paranoid parameter, which sanitizes error messages by
removing "sensitive" information from them (such as hostnames,
ports, or usernames), as well as clearing "sensitive" data
structures when possible.
A.4.18. Changes in MySQL Connector/J 3.0.0 (31 July 2002)
Bugs fixed:
* General source-code cleanup.
* The driver now only works with JDK-1.2 or newer.
* Fix and sort primary key names in DBMetaData (SF bugs 582086
and 582086).
* ResultSet.getTimestamp() now works for DATE types (SF bug
559134).
* Float types now reported as java.sql.Types.FLOAT (SF bug
579573).
* Support for streaming (row-by-row) result sets (see README)
Thanks to Doron.
* Testsuite now uses Junit (which you can get from
http://www.junit.org.
* JDBC Compliance: Passes all tests besides stored procedure
tests.
* ResultSet.getDate/Time/Timestamp now recognizes all forms of
invalid values that have been set to all zeros by MySQL (SF
bug 586058).
* Added multi-host failover support (see README).
* Repackaging: New driver name is com.mysql.jdbc.Driver, old
name still works, though (the driver is now provided by
MySQL-AB).
* Support for large packets (new addition to MySQL-4.0
protocol), see README for more information.
* Better checking for closed connections in Statement and
PreparedStatement.
* Performance improvements in string handling and field metadata
creation (lazily instantiated) contributed by Alex
Twisleton-Wykeham-Fiennes.
* JDBC-3.0 functionality including
Statement/PreparedStatement.getGeneratedKeys() and
ResultSet.getURL().
* Overall speed improvements via controlling transient object
creation in MysqlIO class when reading packets.
* !!! LICENSE CHANGE !!! The driver is now GPL. If you need
non-GPL licenses, please contact me <mark@mysql.com>.
* Performance enchancements: Driver is now 50-100% faster in
most situations, and creates fewer temporary objects.
A.5. Changes in MySQL Connector/J 2.0.x
A.5.1. Changes in MySQL Connector/J 2.0.14 (16 May 2002)
Bugs fixed:
* ResultSet.getDouble() now uses code built into JDK to be more
precise (but slower).
* Fixed typo for relaxAutoCommit parameter.
* LogicalHandle.isClosed() calls through to physical connection.
* Added SQL profiling (to STDERR). Set profileSql=true in your
JDBC URL. See README for more information.
* PreparedStatement now releases resources on .close(). (SF bug
553268)
* More code cleanup.
* Quoted identifiers not used if server version does not support
them. Also, if server started with --ansi or
--sql-mode=ANSI_QUOTES, """ will be used as an identifier
quote character, otherwise "'" will be used.
A.5.2. Changes in MySQL Connector/J 2.0.13 (24 April 2002)
Bugs fixed:
* Fixed unicode chars being read incorrectly. (SF bug 541088)
* Faster blob escaping for PrepStmt.
* Added setURL() to MySQLXADataSource. (SF bug 546019)
* Added set/getPortNumber() to DataSource(s). (SF bug 548167)
* PreparedStatement.toString() fixed. (SF bug 534026)
* More code cleanup.
* Rudimentary version of Statement.getGeneratedKeys() from
JDBC-3.0 now implemented (you need to be using JDK-1.4 for
this to work, I believe).
* DBMetaData.getIndexInfo() - bad PAGES fixed. (SF BUG 542201)
* ResultSetMetaData.getColumnClassName() now implemented.
A.5.3. Changes in MySQL Connector/J 2.0.12 (07 April 2002)
Bugs fixed:
* Fixed testsuite.Traversal afterLast() bug, thanks to Igor
Lastric.
* Added new types to getTypeInfo(), fixed existing types thanks
to Al Davis and Kid Kalanon.
* Fixed time zone off-by-1-hour bug in PreparedStatement
(538286, 528785).
* Added identifier quoting to all DatabaseMetaData methods that
need them (should fix 518108).
* Added support for BIT types (51870) to PreparedStatement.
* ResultSet.insertRow() should now detect auto_increment fields
in most cases and use that value in the new row. This
detection will not work in multi-valued keys, however, due to
the fact that the MySQL protocol does not return this
information.
* Relaxed synchronization in all classes, should fix 520615 and
520393.
* DataSources - fixed setUrl bug (511614, 525565), wrong
datasource class name (532816, 528767).
* Added support for YEAR type (533556).
* Fixes for ResultSet updatability in PreparedStatement.
* ResultSet: Fixed updatability (values being set to null if not
updated).
* Added getTable/ColumnPrivileges() to DBMD (fixes 484502).
* Added getIdleFor() method to Connection and
MysqlLogicalHandle.
* ResultSet.refreshRow() implemented.
* Fixed getRow() bug (527165) in ResultSet.
* General code cleanup.
A.5.4. Changes in MySQL Connector/J 2.0.11 (27 January 2002)
Bugs fixed:
* Full synchronization of Statement.java.
* Fixed missing DELETE_RULE value in
DBMD.getImported/ExportedKeys() and getCrossReference().
* More changes to fix Unexpected end of input stream errors when
reading BLOB values. This should be the last fix.
A.5.5. Changes in MySQL Connector/J 2.0.10 (24 January 2002)
Bugs fixed:
* Fixed null-pointer-exceptions when using
MysqlConnectionPoolDataSource with Websphere 4 (bug 505839).
* Fixed spurious Unexpected end of input stream errors in
MysqlIO (bug 507456).
A.5.6. Changes in MySQL Connector/J 2.0.9 (13 January 2002)
Bugs fixed:
* Fixed extra memory allocation in MysqlIO.readPacket() (bug
488663).
* Added detection of network connection being closed when
reading packets (thanks to Todd Lizambri).
* Fixed casting bug in PreparedStatement (bug 488663).
* DataSource implementations moved to
org.gjt.mm.mysql.jdbc2.optional package, and (initial)
implementations of PooledConnectionDataSource and XADataSource
are in place (thanks to Todd Wolff for the implementation and
testing of PooledConnectionDataSource with IBM WebSphere 4).
* Fixed quoting error with escape processor (bug 486265).
* Removed concatenation support from driver (the || operator),
as older versions of VisualAge seem to be the only thing that
use it, and it conflicts with the logical || operator. You
will need to start mysqld with the --ansi flag to use the ||
operator as concatenation (bug 491680).
* Ant build was corrupting included jar files, fixed (bug
487669).
* Report batch update support through DatabaseMetaData (bug
495101).
* Implementation of DatabaseMetaData.getExported/ImportedKeys()
and getCrossReference().
* Fixed off-by-one-hour error in
PreparedStatement.setTimestamp() (bug 491577).
* Full synchronization on methods modifying instance and
class-shared references, driver should be entirely thread-safe
now (please let me know if you have problems).
A.5.7. Changes in MySQL Connector/J 2.0.8 (25 November 2001)
Bugs fixed:
* XADataSource/ConnectionPoolDataSource code (experimental)
* DatabaseMetaData.getPrimaryKeys() and getBestRowIdentifier()
are now more robust in identifying primary keys (matches
regardless of case or abbreviation/full spelling of Primary
Key in Key_type column).
* Batch updates now supported (thanks to some inspiration from
Daniel Rall).
* PreparedStatement.setAnyNumericType() now handles positive
exponents correctly (adds + so MySQL can understand it).
A.5.8. Changes in MySQL Connector/J 2.0.7 (24 October 2001)
Bugs fixed:
* Character sets read from database if useUnicode=true and
characterEncoding is not set. (thanks to Dmitry Vereshchagin)
* Initial transaction isolation level read from database (if
avaialable). (thanks to Dmitry Vereshchagin)
* Fixed PreparedStatement generating SQL that would end up with
syntax errors for some queries.
* PreparedStatement.setCharacterStream() now implemented
* Captialize type names when captializeTypeNames=true is passed
in URL or properties (for WebObjects. (thanks to Anjo Krank)
* ResultSet.getBlob() now returns null if column value was null.
* Fixed ResultSetMetaData.getPrecision() returning one less than
actual on newer versions of MySQL.
* Fixed dangling socket problem when in high availability
(autoReconnect=true) mode, and finalizer for Connection will
close any dangling sockets on GC.
* Fixed time zone issue in PreparedStatement.setTimestamp().
(thanks to Erik Olofsson)
* PreparedStatement.setDouble() now uses full-precision doubles
(reverting a fix made earlier to truncate them).
* Fixed DatabaseMetaData.supportsTransactions(), and
supportsTransactionIsolationLevel() and getTypeInfo()
SQL_DATETIME_SUB and SQL_DATA_TYPE fields not being readable.
* Updatable result sets now correctly handle NULL values in
fields.
* PreparedStatement.setBoolean() will use 1/0 for values if your
MySQL version is 3.21.23 or higher.
* Fixed ResultSet.isAfterLast() always returning false.
A.5.9. Changes in MySQL Connector/J 2.0.6 (16 June 2001)
Bugs fixed:
* Fixed PreparedStatement parameter checking.
* Fixed case-sensitive column names in ResultSet.java.
A.5.10. Changes in MySQL Connector/J 2.0.5 (13 June 2001)
Bugs fixed:
* ResultSet.insertRow() works now, even if not all columns are
set (they will be set to NULL).
* Added Byte to PreparedStatement.setObject().
* Fixed data parsing of TIMESTAMP values with 2-digit years.
* Added ISOLATION level support to
Connection.setIsolationLevel()
* DataBaseMetaData.getCrossReference() no longer ArrayIndexOOB.
* ResultSet.getBoolean() now recognizes -1 as true.
* ResultSet has +/-Inf/inf support.
* getObject() on ResultSet correctly does TINYINT->Byte and
SMALLINT->Short.
* Fixed ResultSetMetaData.getColumnTypeName for TEXT/BLOB.
* Fixed ArrayIndexOutOfBounds when sending large BLOB queries.
(Max size packet was not being set)
* Fixed NPE on PreparedStatement.executeUpdate() when all
columns have not been set.
* Fixed ResultSet.getBlob() ArrayIndex out-of-bounds.
A.5.11. Changes in MySQL Connector/J 2.0.3 (03 December 2000)
Bugs fixed:
* Fixed composite key problem with updatable result sets.
* Faster ASCII string operations.
* Fixed off-by-one error in java.sql.Blob implementation code.
* Fixed incorrect detection of MAX_ALLOWED_PACKET, so sending
large blobs should work now.
* Added detection of -/+INF for doubles.
* Added ultraDevHack URL parameter, set to true to allow
(broken) Macromedia UltraDev to use the driver.
* Implemented getBigDecimal() without scale component for JDBC2.
A.5.12. Changes in MySQL Connector/J 2.0.1 (06 April 2000)
Bugs fixed:
* Columns that are of type TEXT now return as Strings when you
use getObject().
* Cleaned up exception handling when driver connects.
* Fixed RSMD.isWritable() returning wrong value. Thanks to
Moritz Maass.
* DatabaseMetaData.getPrimaryKeys() now works correctly with
respect to key_seq. Thanks to Brian Slesinsky.
* Fixed many JDBC-2.0 traversal, positioning bugs, especially
with respect to empty result sets. Thanks to Ron Smits, Nick
Brook, Cessar Garcia and Carlos Martinez.
* No escape processing is done on PreparedStatements anymore per
JDBC spec.
* Fixed some issues with updatability support in ResultSet when
using multiple primary keys.
A.5.13. Changes in MySQL Connector/J 2.0.0pre5 (21 February 2000)
* Fixed Bad Handshake problem.
A.5.14. Changes in MySQL Connector/J 2.0.0pre4 (10 January 2000)
* Fixes to ResultSet for insertRow() - Thanks to Cesar Garcia
* Fix to Driver to recognize JDBC-2.0 by loading a JDBC-2.0
class, instead of relying on JDK version numbers. Thanks to
John Baker.
* Fixed ResultSet to return correct row numbers
* Statement.getUpdateCount() now returns rows matched, instead
of rows actually updated, which is more SQL-92 like.
10-29-99
* Statement/PreparedStatement.getMoreResults() bug fixed. Thanks
to Noel J. Bergman.
* Added Short as a type to PreparedStatement.setObject(). Thanks
to Jeff Crowder
* Driver now automagically configures maximum/preferred packet
sizes by querying server.
* Autoreconnect code uses fast ping command if server supports
it.
* Fixed various bugs with respect to packet sizing when reading
from the server and when alloc'ing to write to the server.
A.5.15. Changes in MySQL Connector/J 2.0.0pre (17 August 1999)
* Now compiles under JDK-1.2. The driver supports both JDK-1.1
and JDK-1.2 at the same time through a core set of classes.
The driver will load the appropriate interface classes at
runtime by figuring out which JVM version you are using.
* Fixes for result sets with all nulls in the first row.
(Pointed out by Tim Endres)
* Fixes to column numbers in SQLExceptions in ResultSet (Thanks
to Blas Rodriguez Somoza)
* The database no longer needs to specified to connect. (Thanks
to Christian Motschke)
A.6. Changes in MySQL Connector/J 1.2b (04 July 1999)
* Better Documentation (in progress), in doc/mm.doc/book1.html
* DBMD now allows null for a column name pattern (not in spec),
which it changes to '%'.
* DBMD now has correct types/lengths for getXXX().
* ResultSet.getDate(), getTime(), and getTimestamp() fixes.
(contributed by Alan Wilken)
* EscapeProcessor now handles \{ \} and { or } inside quotes
correctly. (thanks to Alik for some ideas on how to fix it)
* Fixes to properties handling in Connection. (contributed by
Juho Tikkala)
* ResultSet.getObject() now returns null for NULL columns in the
table, rather than bombing out. (thanks to Ben Grosman)
* ResultSet.getObject() now returns Strings for types from MySQL
that it doesn't know about. (Suggested by Chris Perdue)
* Removed DataInput/Output streams, not needed, 1/2 number of
method calls per IO operation.
* Use default character encoding if one is not specified. This
is a work-around for broken JVMs, because according to spec,
EVERY JVM must support "ISO8859_1", but they don't.
* Fixed Connection to use the platform character encoding
instead of "ISO8859_1" if one isn't explicitly set. This fixes
problems people were having loading the character- converter
classes that didn't always exist (JVM bug). (thanks to Fritz
Elfert for pointing out this problem)
* Changed MysqlIO to re-use packets where possible to reduce
memory usage.
* Fixed escape-processor bugs pertaining to {} inside quotes.
A.7. Changes in MySQL Connector/J 1.2.x and lower
A.7.1. Changes in MySQL Connector/J 1.2a (14 April 1999)
* Fixed character-set support for non-Javasoft JVMs (thanks to
many people for pointing it out)
* Fixed ResultSet.getBoolean() to recognize 'y' & 'n' as well as
'1' & '0' as boolean flags. (thanks to Tim Pizey)
* Fixed ResultSet.getTimestamp() to give better performance.
(thanks to Richard Swift)
* Fixed getByte() for numeric types. (thanks to Ray Bellis)
* Fixed DatabaseMetaData.getTypeInfo() for DATE type. (thanks to
Paul Johnston)
* Fixed EscapeProcessor for "fn" calls. (thanks to Piyush Shah
at locomotive.org)
* Fixed EscapeProcessor to not do extraneous work if there are
no escape codes. (thanks to Ryan Gustafson)
* Fixed Driver to parse URLs of the form
"jdbc:mysql://host:port" (thanks to Richard Lobb)
A.7.2. Changes in MySQL Connector/J 1.1i (24 March 1999)
* Fixed Timestamps for PreparedStatements
* Fixed null pointer exceptions in RSMD and RS
* Re-compiled with jikes for valid class files (thanks ms!)
A.7.3. Changes in MySQL Connector/J 1.1h (08 March 1999)
* Fixed escape processor to deal with unmatched { and } (thanks
to Craig Coles)
* Fixed escape processor to create more portable (between
DATETIME and TIMESTAMP types) representations so that it will
work with BETWEEN clauses. (thanks to Craig Longman)
* MysqlIO.quit() now closes the socket connection. Before, after
many failed connections some OS's would run out of file
descriptors. (thanks to Michael Brinkman)
* Fixed NullPointerException in Driver.getPropertyInfo. (thanks
to Dave Potts)
* Fixes to MysqlDefs to allow all *text fields to be retrieved
as Strings. (thanks to Chris at Leverage)
* Fixed setDouble in PreparedStatement for large numbers to
avoid sending scientific notation to the database. (thanks to
J.S. Ferguson)
* Fixed getScale() and getPrecision() in RSMD. (contrib'd by
James Klicman)
* Fixed getObject() when field was DECIMAL or NUMERIC (thanks to
Bert Hobbs)
* DBMD.getTables() bombed when passed a null table-name pattern.
Fixed. (thanks to Richard Lobb)
* Added check for "client not authorized" errors during connect.
(thanks to Hannes Wallnoefer)
A.7.4. Changes in MySQL Connector/J 1.1g (19 February 1999)
* Result set rows are now byte arrays. Blobs and Unicode work
bidriectonally now. The useUnicode and encoding options are
implemented now.
* Fixes to PreparedStatement to send binary set by setXXXStream
to be sent untouched to the MySQL server.
* Fixes to getDriverPropertyInfo().
A.7.5. Changes in MySQL Connector/J 1.1f (31 December 1998)
* Changed all ResultSet fields to Strings, this should allow
Unicode to work, but your JVM must be able to convert between
the character sets. This should also make reading data from
the server be a bit quicker, because there is now no
conversion from StringBuffer to String.
* Changed PreparedStatement.streamToString() to be more
efficient (code from Uwe Schaefer).
* URL parsing is more robust (throws SQL exceptions on errors
rather than NullPointerExceptions)
* PreparedStatement now can convert Strings to Time/Date values
via setObject() (code from Robert Currey).
* IO no longer hangs in Buffer.readInt(), that bug was
introduced in 1.1d when changing to all byte-arrays for result
sets. (Pointed out by Samo Login)
A.7.6. Changes in MySQL Connector/J 1.1b (03 November 1998)
* Fixes to DatabaseMetaData to allow both IBM VA and J-Builder
to work. Let me know how it goes. (thanks to Jac Kersing)
* Fix to ResultSet.getBoolean() for NULL strings (thanks to
Barry Lagerweij)
* Beginning of code cleanup, and formatting. Getting ready to
branch this off to a parallel JDBC-2.0 source tree.
* Added "final" modifier to critical sections in MysqlIO and
Buffer to allow compiler to inline methods for speed.
9-29-98
* If object references passed to setXXX() in PreparedStatement
are null, setNull() is automatically called for you. (Thanks
for the suggestion goes to Erik Ostrom)
* setObject() in PreparedStatement will now attempt to write a
serialized representation of the object to the database for
objects of Types.OTHER and objects of unknown type.
* Util now has a static method readObject() which given a
ResultSet and a column index will re-instantiate an object
serialized in the above manner.
A.7.7. Changes in MySQL Connector/J 1.1 (02 September 1998)
* Got rid of "ugly hack" in MysqlIO.nextRow(). Rather than catch
an exception, Buffer.isLastDataPacket() was fixed.
* Connection.getCatalog() and Connection.setCatalog() should
work now.
* Statement.setMaxRows() works, as well as setting by property
maxRows. Statement.setMaxRows() overrides maxRows set via
properties or url parameters.
* Automatic re-connection is available. Because it has to "ping"
the database before each query, it is turned off by default.
To use it, pass in "autoReconnect=true" in the connection URL.
You may also change the number of reconnect tries, and the
initial timeout value via "maxReconnects=n" (default 3) and
"initialTimeout=n" (seconds, default 2) parameters. The
timeout is an exponential backoff type of timeout; for
example, if you have initial timeout of 2 seconds, and
maxReconnects of 3, then the driver will timeout 2 seconds, 4
seconds, then 16 seconds between each re-connection attempt.
A.7.8. Changes in MySQL Connector/J 1.0 (24 August 1998)
* Fixed handling of blob data in Buffer.java
* Fixed bug with authentication packet being sized too small.
* The JDBC Driver is now under the LPGL
8-14-98
* Fixed Buffer.readLenString() to correctly read data for BLOBS.
* Fixed PreparedStatement.stringToStream to correctly read data
for BLOBS.
* Fixed PreparedStatement.setDate() to not add a day. (above
fixes thanks to Vincent Partington)
* Added URL parameter parsing (?user=... and so forth).
A.7.9. Changes in MySQL Connector/J 0.9d (04 August 1998)
* Big news! New package name. Tim Endres from ICE Engineering is
starting a new source tree for GNU GPL'd Java software. He's
graciously given me the org.gjt.mm package directory to use,
so now the driver is in the org.gjt.mm.mysql package scheme.
I'm "legal" now. Look for more information on Tim's project
soon.
* Now using dynamically sized packets to reduce memory usage
when sending commands to the DB.
* Small fixes to getTypeInfo() for parameters, and so forth.
* DatabaseMetaData is now fully implemented. Let me know if
these drivers work with the various IDEs out there. I've heard
that they're working with JBuilder right now.
* Added JavaDoc documentation to the package.
* Package now available in .zip or .tar.gz.
A.7.10. Changes in MySQL Connector/J 0.9 (28 July 1998)
* Implemented getTypeInfo(). Connection.rollback() now throws an
SQLException per the JDBC spec.
* Added PreparedStatement that supports all JDBC API methods for
PreparedStatement including InputStreams. Please check this
out and let me know if anything is broken.
* Fixed a bug in ResultSet that would break some queries that
only returned 1 row.
* Fixed bugs in DatabaseMetaData.getTables(),
DatabaseMetaData.getColumns() and
DatabaseMetaData.getCatalogs().
* Added functionality to Statement that allows executeUpdate()
to store values for IDs that are automatically generated for
AUTO_INCREMENT fields. Basically, after an executeUpdate(),
look at the SQLWarnings for warnings like "LAST_INSERTED_ID =
'some number', COMMAND = 'your SQL query'". If you are using
AUTO_INCREMENT fields in your tables and are executing a lot
of executeUpdate()s on one Statement, be sure to
clearWarnings() every so often to save memory.
A.7.11. Changes in MySQL Connector/J 0.8 (06 July 1998)
* Split MysqlIO and Buffer to separate classes. Some
ClassLoaders gave an IllegalAccess error for some fields in
those two classes. Now mm.mysql works in applets and all
classloaders. Thanks to Joe Ennis <jce@mail.boone.com> for
pointing out the problem and working on a fix with me.
A.7.12. Changes in MySQL Connector/J 0.7 (01 July 1998)
* Fixed DatabaseMetadata problems in getColumns() and bug in
switch statement in the Field constructor. Thanks to Costin
Manolache <costin@tdiinc.com> for pointing these out.
A.7.13. Changes in MySQL Connector/J 0.6 (21 May 1998)
* Incorporated efficiency changes from Richard Swift
<Richard.Swift@kanatek.ca> in MysqlIO.java and ResultSet.java:
* We're now 15% faster than gwe's driver.
* Started working on DatabaseMetaData.
* The following methods are implemented:
+ getTables()
+ getTableTypes()
+ getColumns()
+ getCatalogs()
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