Copyright © 2004, 2005 MySQL AB
This manual is NOT distributed under a GPL style license. Use of the manual is subject to the following terms:
Conversion to other formats is allowed, but the actual content may not be altered or edited in any way.
You may create a printed copy for your own personal use.
For all other uses, such as selling printed copies or using (parts of) the manual in another publication, prior written agreement from MySQL AB is required.
MySQL and the MySQL logo are (registered) trademarks of MySQL AB. Other trademarks and registered trademarks referred to in this manual are the property of their respective owners, and are used for identification purposes only.
Table of Contents
List of Tables
List of Examples
Table of Contents
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-3.0 "Type 4" driver, which means that is is pure Java, implements version 3.0 of the JDBC specification, and communicates directly with the MySQL server using the MySQL protocol.
This document is arranged for a beginning JDBC developer. If you are already experienced with using JDBC, you might consider starting with the section "Installing Connector/J".
While JDBC is useful by itself, we would hope that if you are not familiar with JDBC that after reading the first few chapters 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 , Spring's JDBC templates or Ibatis SQL Maps to do the majority of repetitive work and heavier lifting that is sometimes required with JDBC.
This chapter 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 - A tutorial from Sun covering beginner topics in JDBC
JDBC Short Course - A more in-depth tutorial from Sun and JGuru
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 1.1. 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 Statements and PreparedStatements, as well as retrieve metadata about the database. This is explained in the following sections.
Statements 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 an UPDATE/INSERT/DELETE query. If the query was a SELECT query, you can retrieve the results by calling the getResultSet() method. If the query was an UPDATE/INSERT/DELETE query, you can retrieve the affected rows count by calling getUpdateCount() on the Statement instance.
Example 1.2. Using java.sql.Statement to Execute a SELECT Query
// assume 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;
}
}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.
MySQL's stored procedure syntax is documented in the "Stored Procedures and Functions" section of the MySQL Reference Manual.
Connector/J exposes stored procedure functionality through JDBC's CallableStatement interface.
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 1.3. Stored Procedure Example
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);
ENDTo use the demoSp procedure with Connector/J, follow these steps:
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 1.4. 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");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.
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 1.5. 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
//
cStmt.registerOutParameter(2);
//
// 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'
//
cStmt.registerOutParameter("inOutParam");
//
// Registers the named parameter 'inOutParam', and
// uses the type 'INTEGER' for values returned from
// getObject()
//
cStmt.registerOutParameter("inOutParam", Types.INTEGER);
...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 1.6. 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);
...Execute the CallableStatement, and retrieve any result sets or output parameters.
While 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 1.7. 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(1); // index-based
outputValue = cStmt.getInt("inOutParam"); // name-based
...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 method 'insertRow()'.
Example 1.8. 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 1.9. 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 1.10. 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
}
}
}
MySQL Connector/J supports Java-2 JVMs, including JDK-1.2.x, JDK-1.3.x, JDK-1.4.x and JDK-1.5.x, and requires JDK-1.4.x or newer to compile (but not run). 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 (-Xverify:none), as 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.
MySQL Connector/J supports all known MySQL server versions. Some features (foreign keys, updatable result sets) require more recent versions of MySQL to operate.
When connecting to MySQL server version 4.1 or newer, it is best to use MySQL Connector/J version 3.1, as it has full support for features in the newer versions of the server, including Unicode characters, views, stored procedures and server-side prepared statements.
While Connector/J version 3.0 will connect to MySQL server, version 4.1 or newer, and implements Unicode characters and the new authorization mechanism, Connector/J 3.0 will not be updated to support new features in current and future server versions.
MySQL Connector/J is distributed as a .zip or .tar.gz archive containing the sources, the class files a class-file only "binary" .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, 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 do 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.
You will need to use the appropriate gui or command-line utility to un-archive 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.
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 enviornment variable, or by directly specifying it with the commandline 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.
Example 1.11. Setting the CLASSPATH Under UNIX
The following command works for 'csh' under UNIX:
$ setenv CLASSPATH /path/to/mysql-connector-java-[version]-bin.jar:$CLASSPATH
The above command can be added to the appropriate startup file for the login shell to make MySQL Connector/J available to all Java applications.
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. This document does contain configuration examples for some J2EE application servers in the section named "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 and/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. 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
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.
Connector/J 3.1 is designed to be backwards-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 the "Character Sets" section in the server manual 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 following 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 a SQLException with a 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'.
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 timezone 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 than 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 following configuration property:
useSqlStateCodes=false
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.
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 do 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.
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
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 backwards-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 'current' 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:
com.mysql.jdbc.jdbc2.optional.MysqlDataSource
com.mysql.jdbc.jdbc2.optional.MysqlConnectionPoolDataSource
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 javax.sql.DataSource's setURL() method.
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.
Table 1.1. Connection Properties
| Property Name | Definition | Required? | Default Value | Since Version |
|---|---|---|---|---|
| Connection/Authentication | ||||
| user | The user to connect as | No | all | |
| password | The password to use when connecting | No | all | |
| 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. | No | 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'. | No | 0 | 3.0.1 |
| socketTimeout | Timeout on network socket operations (0, the default means no timeout). | No | 0 | 3.0.1 |
| 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. | No | 3.1.5 | |
| interactiveClient | Set the CLIENT_INTERACTIVE flag, which tells MySQL to timeout connections based on INTERACTIVE_TIMEOUT instead of WAIT_TIMEOUT | No | false | 3.1.0 |
| 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 | No | 3.1.4 | |
| useCompression | Use zlib compression when communicating with the server (true/false)? Defaults to 'false'. | No | false | 3.0.17 |
| High Availability and Clustering | ||||
| autoReconnect | Should the driver try to re-establish bad connections? | No | false | 1.1 |
| autoReconnectForPools | Use a reconnection strategy appropriate for connection pools (defaults to 'false') | No | false | 3.1.3 |
| failOverReadOnly | When failing over in autoReconnect mode, should the connection be set to 'read-only'? | No | true | 3.0.12 |
| reconnectAtTxEnd | If autoReconnect is set to true, should the driver attempt reconnectionsat the end of every transaction? | No | false | 3.0.10 |
| roundRobinLoadBalance | When autoReconnect is enabled, and failoverReadonly is false, should we pick hosts to connect to on a round-robin basis? | No | 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. | No | 50 | 3.0.2 |
| secondsBeforeRetryMaster | How long should the driver wait, when failed over, before attempting to reconnect to the master server? Whichever condition is met first, 'queriesBeforeRetryMaster' or 'secondsBeforeRetryMaster' will cause an attempt to be made to reconnect to the master. Time in seconds, defaults to 30 | No | 30 | 3.0.2 |
| enableDeprecatedAutoreconnect | Auto-reconnect functionality is deprecated starting with version 3.2, and will be removed in version 3.3. Set this property to 'true' to disable the check for the feature being configured. | No | false | 3.2.1 |
| Security | ||||
| allowMultiQueries | Allow the use of ';' to delimit multiple queries during one statement (true/false, defaults to 'false' | No | false | 3.1.1 |
| useSSL | Use SSL when communicating with the server (true/false), defaults to 'false' | No | false | 3.0.2 |
| requireSSL | Require SSL connection if useSSL=true? (defaults to 'false'). | No | false | 3.1.0 |
| allowUrlInLocalInfile | Should the driver allow URLs in 'LOAD DATA LOCAL INFILE' statements? | No | false | 3.1.4 |
| paranoid | Take measures to prevent exposure sensitive information in error messages and clear data structures holding sensitive data when possible? (defaults to 'false') | No | false | 3.0.1 |
| Performance Extensions | ||||
| metadataCacheSize | The number of queries to cacheResultSetMetadata for if cacheResultSetMetaData is set to 'true' (default 50) | No | 50 | 3.1.1 |
| prepStmtCacheSize | If prepared statement caching is enabled, how many prepared statements should be cached? | No | 25 | 3.0.10 |
| prepStmtCacheSqlLimit | If prepared statement caching is enabled, what's the largest SQL the driver will cache the parsing for? | No | 256 | 3.0.10 |
| 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. | No | true | 3.1.9 |
| blobSendChunkSize | Chunk to use when sending BLOB/CLOBs via ServerPreparedStatements | No | 1048576 | 3.1.9 |
| cacheCallableStmts | Should the driver cache the parsing stage of CallableStatements | No | 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? | No | false | 3.0.10 |
| cacheResultSetMetadata | Should the driver cache ResultSetMetaData for Statements and PreparedStatements? (Req. JDK-1.4+, true/false, default 'false') | No | false | 3.1.1 |
| cacheServerConfiguration | Should the driver cache the results of 'SHOW VARIABLES' and 'SHOW COLLATION' on a per-URL basis? | No | false | 3.1.5 |
| 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. | No | false | 3.1.7 |
| dynamicCalendars | Should the driver retrieve the default calendar when required, or cache it per connection/session? | No | 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)? | No | false | 3.1.3 |
| holdResultsOpenOverStatementClose | Should the driver close result sets on Statement.close() as required by the JDBC specification? | No | false | 3.1.7 |
| locatorFetchBufferSize | If 'emulateLocators' is configured to 'true', what size buffer should be used when fetching BLOB data for getBinaryInputStream? | No | 1048576 | 3.2.1 |
| useFastIntParsing | Use internal String->Integer conversion routines to avoid excessive object creation? | No | true | 3.1.4 |
| useLocalSessionState | Should the driver refer to the internal values of autocommit and transaction isolation that are set by Connection.setAutoCommit() and Connection.setTransactionIsolation(), rather than querying the database? | No | false | 3.1.7 |
| useNewIO | Should the driver use the java.nio.* interfaces for network communication (true/false), defaults to 'false' | No | false | 3.1.0 |
| useReadAheadInput | Use newer, optimized non-blocking, buffered input stream when reading from the server? | No | true | 3.1.5 |
| Debuging/Profiling | ||||
| 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) | No | com.mysql.jdbc.log.StandardLogger | 3.1.1 |
| profileSQL | Trace queries and their execution/fetch times to the configured logger (true/false) defaults to 'false' | No | false | 3.1.0 |
| reportMetricsIntervalMillis | If 'gatherPerfMetrics' is enabled, how often should they be logged (in ms)? | No | 30000 | 3.1.2 |
| maxQuerySizeToLog | Controls the maximum length/size of a query that will get logged when profiling or tracing | No | 2048 | 3.1.3 |
| packetDebugBufferSize | The maximum number of packets to retain when 'enablePacketDebug' is true | No | 20 | 3.1.3 |
| slowQueryThresholdMillis | If 'logSlowQueries' is enabled, how long should a query (in ms) before it is logged as 'slow'? | No | 2000 | 3.1.2 |
| 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')? | No | false | 3.1.1 |
| autoGenerateTestcaseScript | Should the driver dump the SQL it is executing, including server-side prepared statements to STDERR? | No | false | 3.1.9 |
| dumpQueriesOnException | Should the driver dump the contents of the query sent to the server in the message for SQLExceptions? | No | 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 | No | 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? | No | false | 3.1.2 |
| logSlowQueries | Should queries that take longer than 'slowQueryThresholdMillis' be logged? | No | false | 3.1.2 |
| traceProtocol | Should trace-level network protocol be logged? | No | false | 3.1.2 |
| Miscellaneous | ||||
| 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' | No | false | 1.1g |
| characterEncoding | If 'useUnicode' is set to true, what character encoding should the driver use when dealing with strings? (defaults is to 'autodetect') | No | 1.1g | |
| characterSetResults | Character set to tell the server to return results as. | No | 3.0.13 | |
| connectionCollation | If set, tells the server to use this collation via 'set connection_collation' | No | 3.0.13 | |
| sessionVariables | A comma-separated list of name/value pairs to be sent as SET SESSION ... to the server when the driver connects. | No | 3.1.8 | |
| allowNanAndInf | Should the driver allow NaN or +/- INF values in PreparedStatement.setDouble()? | No | false | 3.1.5 |
| autoDeserialize | Should the driver automatically detect and de-serialize objects stored in BLOB fields? | No | false | 3.1.5 |
| capitalizeTypeNames | Capitalize type names in DatabaseMetaData? (usually only useful when using WebObjects, true/false, defaults to 'false') | No | false | 2.0.7 |
| 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. | No | 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'). | No | 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. | No | false | 3.1.9 |
| emptyStringsConvertToZero | Should the driver allow conversions from empty string fields to numeric values of '0'? | No | true | 3.1.8 |
| emulateLocators | N/A | No | 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? | No | true | 3.1.7 |
| ignoreNonTxTables | Ignore non-transactional table warning for rollback? (defaults to 'false'). | No | 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)? | No | true | 3.1.2 |
| maxRows | The maximum number of rows to return (0, the default means return all rows). | No | -1 | all versions |
| noDatetimeStringSync | Don't ensure that ResultSet.getDatetimeType().toString().equals(ResultSet.getString()) | No | false | 3.1.7 |
| 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) | No | 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) | No | true | 3.1.8 |
| pedantic | Follow the JDBC spec to the letter. | No | false | 3.0.0 |
| 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')? | No | false | 2.0.13 |
| rollbackOnPooledClose | Should the driver issue a rollback() when the logical connection in a pool is closed? | No | true | 3.0.15 |
| runningCTS13 | Enables workarounds for bugs in Sun's JDBC compliance testsuite version 1.3 | No | false | 3.1.7 |
| serverTimezone | Override detection/mapping of timezone. Used when timezone from server doesn't map to Java timezone | No | 3.0.2 | |
| strictFloatingPoint | Used only in older versions of compliance test | No | false | 3.0.0 |
| strictUpdates | Should the driver do strict checking (all primary keys selected) of updatable result sets (true, false, defaults to 'true')? | No | 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)? | No | 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? | No | false | 3.1.9 |
| ultraDevHack | Create PreparedStatements for prepareCall() when required, because UltraDev is broken and issues a prepareCall() for _all_ statements? (true/false, defaults to 'false') | No | false | 2.0.3 |
| useHostsInPrivileges | Add '@hostname' to users in DatabaseMetaData.getColumn/TablePrivileges() (true/false), defaults to 'true'. | No | true | 3.0.2 |
| useOldUTF8Behavior | Use the UTF-8 behavior the driver did when communicating with 4.0 and older servers | No | false | 3.1.6 |
| useOnlyServerErrorMessages | Don't prepend 'standard' SQLState error messages to error messages returned by the server. | No | true | 3.0.15 |
| useServerPrepStmts | Use server-side prepared statements if the server supports them? (defaults to 'true'). | No | true | 3.1.0 |
| useSqlStateCodes | Use SQL Standard state codes instead of 'legacy' X/Open/SQL state codes (true/false), default is 'true' | No | true | 3.1.3 |
| useStreamLengthsInPrepStmts | Honor stream length parameter in PreparedStatement/ResultSet.setXXXStream() method calls (true/false, defaults to 'true')? | No | true | 3.0.2 |
| useTimezone | Convert time/date types between client and server timezones (true/false, defaults to 'false')? | No | false | 3.0.2 |
| useUnbufferedInput | Don't use BufferedInputStream for reading data from the server | No | true | 3.0.11 |
| yearIsDateType | Should the JDBC driver treat the MySQL type "YEAR" as a java.sql.Date, or as a SHORT? | No | 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'. | No | 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.
Adding the following property to your URL will enable the NamedPipeSocketFactory:
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.
MySQL Connector/J passes all of the tests in the publicly-available version of Sun's JDBC compliance testsuite. 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
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.
Starting with Connector/J version 3.1.0, you can emulate Blobs with locators by adding the property 'emulateLocators=true' to your JDBC URL. You must then use a column alias with the value of the column set to the actual name of the Blob column in the SELECT that you write to retrieve the Blob. The SELECT must also reference only one table, the table must have a primary key, and the SELECT must cover all columns that make up the primary key. The driver will then delay loading the actual Blob data until you retrieve the Blob and call retrieval methods (getInputStream(), getBytes(), etc) on it.
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 (getImported/ExportedKeys() and getCrossReference()) is only available from 'InnoDB'-type tables. However, the driver uses 'SHOW CREATE TABLE' to retrieve this information, so when other table types support foreign keys, the driver will transparently support them as well.
Driver
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:
The driver streams the 'large' data 'out-of-band' to the prepared statement on the server side when the parameter is set (before execution of the prepared statement).
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.
MySQL does not support SQL cursors, and the JDBC driver doesn't emulate them, so "setCursorName()" has no effect.
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:
Table 1.2. Conversion Table
| 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.BigDecimalNoteround-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. |
| DATE, TIME, DATETIME, TIMESTAMP | java.lang.String, java.sql.Date, java.sql.Timestamp |
The ResultSet.getObject() method uses the following type conversions between MySQL and Java types, following the JDBC specification where appropriate:
Table 1.3. MySQL Types to Java Types for ResultSet.getObject()
| MySQL Type Name | Returned as Java Class |
|---|---|
| BIT(1) (new in MySQL-5.0) | java.lang.Boolean |
| BIT( > 1) (new in MySQL-5.0) | byte[] |
| 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 | See TINYINT, above as these are aliases for TINYINT(1), currently. |
| SMALLINT[(M)] [UNSIGNED] | java.lang.Integer (regardless if UNSIGNED or not) |
| MEDIUMINT[(M)] [UNSIGNED] | java.lang.Integer (regardless if UNSIGNED or not) |
| INT,INTEGER[(M)] [UNSIGNED] | java.lang.Integer, if UNSIGNED java.lang.Long |
| BIGINT[(M)] [UNSIGNED] | java.lang.Long, if UNSIGNED java.math.BigInteger |
| FLOAT[(M,D)] | java.lang.Float |
| DOUBLE[(M,B)] | java.lang.Double |
| DECIMAL[(M[,D])] | java.math.BigDecimal |
| DATE | java.sql.Date |
| DATETIME | java.sql.Timestamp |
| TIMESTAMP[(M)] | java.sql.Timestamp |
| TIME | java.sql.Time |
| YEAR[(2|4)] | java.sql.Date (with the date set two January 1st, at midnight) |
| CHAR(M) | java.lang.String (unless the character set for the column is BINARY, then byte[] is returned. |
| VARCHAR(M) [BINARY] | java.lang.String (unless the character set for the column is BINARY, then byte[] is returned. |
| BINARY(M) | byte[] |
| VARBINARY(M) | byte[] |
| TINYBLOB | byte[] |
| TINYTEXT | java.lang.String |
| BLOB | byte[] |
| TEXT | java.lang.String |
| MEDIUMBLOB | byte[] |
| MEDIUMTEXT | java.lang.String |
| LONGBLOB | byte[] |
| LONGTEXT | java.lang.String |
| ENUM('value1','value2',...) | java.lang.String |
| SET('value1','value2',...) | java.lang.String |
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(), setAsiiStream(), 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 configuration variable 'character_set' for server versions older than 4.1.0 and 'character_set_server' for server versions 4.1.0 and newer. See the "Server Character Set and Collation" section in the MySQL server manual for more information.
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:
Table 1.4. MySQL to Java Encoding Name Translations
| MySQL Character Set Name | Java-Style Character Encoding Name |
|---|---|
| usa7 | US-ASCII |
| big5 | Big5 |
| gbk | GBK |
| sjis | SJIS |
| gb2312 | EUC_CN |
| ujis | EUC_JP |
| euc_kr | EUC_KR |
| latin1 | ISO8859_1 |
| latin1_de | ISO8859_1 |
| german1 | ISO8859_1 |
| danish | ISO8859_1 |
| latin2 | ISO8859_2 |
| czech | ISO8859_2 |
| hungarian | ISO8859_2 |
| croat | ISO8859_2 |
| greek | ISO8859_7 |
| hebrew | ISO8859_8 |
| latin5 | ISO8859_9 |
| latvian | ISO8859_13 |
| latvian1 | ISO8859_13 |
| estonia | ISO8859_13 |
| dos | Cp437 |
| pclatin2 | Cp852 |
| cp866 | Cp866 |
| koi8_ru | KOI8_R |
| tis620 | TIS620 |
| win1250 | Cp1250 |
| win1250ch | Cp1250 |
| win1251 | Cp1251 |
| cp1251 | Cp1251 |
| win1251ukr | Cp1251 |
| cp1257 | Cp1257 |
| macroman | MacRoman |
| macce | MacCentralEurope |
| utf8 | UTF-8 |
| ucs2 | UnicodeBig |
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.
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: http://www.mysql.com/doc/en/Secure_connections.html
A client certificate (covered later in this section)
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.
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. It's located in the 'bin' subdirectory of your JDK or JRE):
shell> keytool -import -alias mysqlServerCACert -file cacert.pem -keystore truststore
Keytool will respond with the following information:
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=Som
e-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 keystoreYou will then need to generate a client certificate, so that the MySQL server knows that it is talking to a secure client:
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.
-Djavax.net.ssl.keyStore=path_to_keystore_file -Djavax.net.ssl.keyStorePassword=********* -Djavax.net.ssl.trustStore=path_to_truststore_file -Djavax.net.ssl.trustStorePassword=*********
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.
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 one
// from the list
//
conn.setReadOnly(true);
ResultSet rs = conn.createStatement().executeQuery("SELECT a,b,c FROM some_other_table");
.......
}
}
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
While 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, etc) 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 1.12. 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 instances
* 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 here
}
stmt = null;
}
if (conn != null) {
try {
conn.close();
} catch (sqlexception sqlex) {
// ignore -- as we can't do anything about it here
}
conn = null;
}
}
}
}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, etc), connections, and anything created by them (statements, result sets, etc) 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 (buffers, locks, sockets, etc) 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." While 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 backwards from there to determine what values of minimum and maximum pooled connections give the best performance for your particular application.
The following instructions are based on the instructions for Tomcat-5.x, available at http://jakarta.apache.org/tomcat/tomcat-5.0-doc/jndi-datasource-examples-howto.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 if your application is
supposed to deal with SQLExceptions (hint, it should), and
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 applications
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 ' SQL state: null
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 name
"java:/MySQLDB" -->
<jndi-name>MySQLDB</jndi-name>
<connection-url>jdbc:mysql://localhost:3306/dbname</connection-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> 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. If you have further issues, see the "SUPPORT" section.
| 1.5.1.1. | 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 or not the connection should be allowed. You must add grants to allow this to happen. The following is an example of how to do this (but not the most secure). From the mysql command-line client, logged in as a user that can grant privileges, issue the following command: GRANT ALL PRIVILEGES ON [dbname].* to
'[user]'@'[hostname]' identified by
'[password]'replacing [dbname] with the name of your database, [user] with the user name, [hostname] with the host that MySQL Connector/J will be connecting from, and [password] with the password you want to use. Be aware that RedHat Linux is broken with respect to the hostname portion for the case when you are connecting from localhost. You need to use "localhost.localdomain" for the [hostname] value in this case. Follow this by issuing the "FLUSH PRIVILEGES" command. NoteTesting 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. WarningIf you don't understand what the 'GRANT' command does, or how it works, you should read and understand the 'General Security Issues and the MySQL Access Privilege System' section of the MySQL manual before attempting to change privileges. Changing privileges and permissions improperly in MySQL can potentially cause your server installation to not have optimal security properties. | |
| 1.5.1.2. | My application throws a SQLException 'No Suitable Driver'. Why is this happening? |
One of two things are happening. Either the driver is not in your CLASSPATH (see the "INSTALLATION" section above), or your URL format is incorrect (see "Developing Applications with MySQL Connector/J"). | |
| 1.5.1.3. | 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). | |
| 1.5.1.4. | 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 "Developing Applications with MySQL 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 1.13. 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 going
// 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 41000 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) || "41000".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));
} | |
| 1.5.1.5. | 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 all of the primary key(s) and the query can only span one table (i.e. no joins). This is outlined in the JDBC specification. |
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.
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/.# Changelog
# $Id: CHANGES,v 1.38.4.206 2005/05/12 15:25:54 mmatthews Exp $
05-17-05 - Version 3.2.1-alpha
- Autoreconnect functionality (i.e. autoReconnect=true) is now deprecated.
An exception will be thrown if you try and use it, use
'enableDeprecatedAutoreconnect=true' to still use autoReconnect. However
this feature will be removed in Connector/J 3.3, see the manual for
solutions that don't require autoReconnect to be used.
- Driver now checks if server variable 'init_connect' is set, and if so
checks autocommit setting, and applies it.
- If connected to server > 5.0.x, and Statement.setFetchSize( > 0), the
driver will try and use server prepared statements and fetch
statements using result set 'cursors'.
- 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 one megabyte).
- Support sql mode NO_BACKSLASH_ESCAPES with non-server-side prepared
statements.
12-23-04 - Version 3.2.0-alpha
- Fixed incorrect return values from DatabaseMetaData.supportsCatalogIn*().
- Support for 'cursor' based result sets when using ServerPreparedStatements
and MySQL 5.0 or newer. Result set needs to be forward-only, and a non-zero
fetch size for this feature to be enabled.
- Refactoring of where logic for prepared statement, server-prepared
statement lives.
06-23-05 - Version 3.1.10-stable
- Fixed connecting without a database specified raised an exception
in MysqlIO.changeDatabaseTo().
- 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.
06-22-05 - Version 3.1.9-stable
- Overhaul of character set configuration, everything now
lives in a properties file.
- 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.
- Fixed BUG#9064 - com.mysql.jdbc.PreparedStatement.ParseInfo
does unnecessary call to toCharArray().
- Fixed Bug#10144 - Memory leak in ServerPreparedStatement if
serverPrepare() fails.
- Actually write manifest file to correct place so it ends up
in the binary jar file.
- 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.
- Fixed BUG#10156 - 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.
- Fixed BUG#10155, double quotes not recognized when parsing
client-side prepared statements.
- Made enableStreamingResults() visible on
com.mysql.jdbc.jdbc2.optional.StatementWrapper.
- Made ServerPreparedStatement.asSql() work correctly so auto-explain
functionality would work with server-side prepared statements.
- Made JDBC2-compliant wrappers public in order to allow access to
vendor extensions.
- 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.
- DatabaseMetaData.supportsMultipleOpenResults() now returns true. The
driver has supported this for some time, DBMD just missed that fact.
- Fixed BUG#10310 - Driver doesn't support {?=CALL(...)} for calling
stored functions. This involved adding support for function retrieval
to DatabaseMetaData.getProcedures() and getProcedureColumns() as well.
- Fixed BUG#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.
- 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. Irregardless 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".
- Fixed BUG#10496 - SQLException is thrown when using property
"characterSetResults" with cp932 or eucjpms.
- Reorganized directory layout, sources now in "src" folder,
don't pollute parent directory when building, now output goes
to "./build", distribution goes to "./dist".
- Added support/bug hunting feature that generates .sql test
scripts to STDERR when "autoGenerateTestcaseScript" is set
to "true".
- Fixed BUG#10850 - 0-length streams not sent to server when
using server-side prepared statements.
- 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.
- 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.
- Don't send COM_RESET_STMT for each execution of a server-side
prepared statement if it isn't required.
- 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.
- Fixed BUG#11115, Varbinary data corrupted when using server-side
prepared statements and ResultSet.getBytes().
- 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.
- 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
- 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.
- Fixed BUG#11259, autoReconnect ping causes exception on connection
startup.
- Fixed BUG#11360 Connector/J dumping query into SQLException twice
- Fixed PreparedStatement.setClob() not accepting null as a parameter.
- Fixed BUG#11411 - Production package doesn't include JBoss integration
classes.
- Removed nonsensical "costly type conversion" warnings when using
usage advisor.
04-14-05 - Version 3.1.8-stable
- Fixed DatabaseMetaData.getTables() returning views when they were
not asked for as one of the requested table types.
- Added support for new precision-math DECIMAL type in MySQL >= 5.0.3.
- Fixed ResultSet.getTime() on a NULL value for server-side prepared
statements throws NPE.
- Made Connection.ping() a public method.
- Fixed Bug#8868, DATE_FORMAT() queries returned as BLOBs from getObject().
- 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 one megabyte).
- BlobFromLocator now uses correct identifier quoting when generating
prepared statements.
- Server-side session variables can be preset at connection time by
passing them as a comma-delimited list for the connection property
'sessionVariables'.
- Fixed regression in ping() for users using autoReconnect=true.
- Fixed BUG#9040 - PreparedStatement.addBatch() doesn't work with server-side
prepared statements and streaming BINARY data.
- Fixed BUG#8800 - DBMD.supportsMixedCase*Identifiers() returns wrong
value on servers running on case-sensitive filesystems.
- Fixed BUG#9206, can not use 'UTF-8' for characterSetResults
configuration property.
- Fixed BUG#9236, a continuation of BUG#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().
- Fixed BUG#8792 - DBMD.supportsResultSetConcurrency() not returning
true for forward-only/read-only result sets (we obviously support this).
- Fixed BUG#8803, 'DATA_TYPE' column from DBMD.getBestRowIdentifier()
causes ArrayIndexOutOfBoundsException when accessed (and in fact, didn't
return any value).
- Check for empty strings ('') when converting char/varchar column data to numbers,
throw exception if 'emptyStringsConvertToZero' configuration property is set
to 'false' (for backwards-compatibility with 3.0, it is now set to 'true'
by default, but will most likely default to 'false' in 3.2).
- Fixed BUG#9320 - PreparedStatement.getMetaData() inserts blank row in database
under certain conditions when not using server-side prepared statements.
- 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.
- Fixed build.xml to not compile log4j logging if log4j not available.
- 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'.
- 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.
- Fixed BUG#9319 - Stored procedures with same name in
different databases confuse the driver when it tries to determine
parameter counts/types.
- 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.
- Fixed BUG#9682 - Stored procedures with DECIMAL parameters with
storage specifications that contained "," in them would fail.
- PreparedStatement.setObject(int, Object, int type, int scale) now
uses scale value for BigDecimal instances.
- Fixed BUG#9704 - Statement.getMoreResults() could throw NPE when
existing result set was .close()d.
- The performance metrics feature now gathers information about
number of tables referenced in a SELECT.
- 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:
Log4j, if it's available,
Then JDK1.4 logging,
Then fallback to our STDERR logging.
- Fixed BUG#9778, DBMD.getTables() shouldn't return tables if views
are asked for, even if the database version doesn't support views.
- Fixed driver not returning 'true' for '-1' when ResultSet.getBoolean()
was called on result sets returned from server-side prepared statements.
- Added a Manifest.MF file with implementation information to the .jar
file.
- More tests in Field.isOpaqueBinary() to distinguish opaque binary (i.e.
fields with type CHAR(n) and CHARACTER SET BINARY) from output of
various scalar and aggregate functions that return strings.
- Fixed BUG#9917 - 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).
- Fixed BUG#9769 - 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).
02-18-05 - Version 3.1.7-stable
- Fixed BUG#7686, Timestamp key column data needed "_binary'"
stripped for UpdatableResultSet.refreshRow().
- Fixed BUG#7715 - Timestamps converted incorrectly to strings
with Server-side prepared statements and updatable result sets.
- Detect new sql_mode variable in string form (it used to be
integer) and adjust quoting method for strings appropriately.
- Added 'holdResultsOpenOverStatementClose' property (default is
false), that keeps result sets open over statement.close() or new
execution on same statement (suggested by Kevin Burton).
- Fixed BUG#7952 -- Infinite recursion when 'falling back' to master
in failover configuration.
- 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.
- Fixed duplicated code in configureClientCharset() that prevented
useOldUTF8Behavior=true from working properly.
- Removed 'dontUnpackBinaryResults' functionality, the driver now
always stores results from server-side prepared statements as-is
from the server and unpacks them on demand.
- Fixed BUG#8096 where emulated locators corrupt binary data
when using server-side prepared statements.
- Fixed synchronization issue with
ServerPreparedStatement.serverPrepare() that could cause
deadlocks/crashes if connection was shared between threads.
- 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 (BUG#4718). You can
disable this by passing 'emulateUnsupportedPstmts=false' in your
JDBC URL.
- Remove _binary introducer from parameters used as in/out
parameters in CallableStatement.
- Always return byte[]s for output parameters registered as *BINARY.
- Send correct value for 'boolean' "true" to server for
PreparedStatement.setObject(n, "true", Types.BIT).
- Fixed bug with Connection not caching statements from
prepareStatement() when the statement wasn't a server-side
prepared statement.
- Choose correct 'direction' to apply time adjustments when both
client and server are in GMT timezone when using
ResultSet.get(..., cal) and PreparedStatement.set(...., cal).
- Added 'dontTrackOpenResources' option (default is false, to be
JDBC compliant), which helps with memory use for non-well-behaved
apps (i.e applications which don't close Statements when they
should).
- Fixed BUG#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').
- Fixed NPE in ResultSet.realClose() when using usage advisor and
result set was already closed.
- Fixed BUG#8487 - PreparedStatements not creating streaming result
sets.
- Don't pass NULL to String.valueOf() in
ResultSet.getNativeConvertToString(), as it stringifies it (i.e.
returns "null"), which is not correct for the method in question.
- Fixed BUG#8484 - 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.
- 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.
- 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.
- 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.
12-23-04 - Version 3.1.6-stable
- 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.
- Fixed BUG#7026 - DBMD.getProcedures() doesn't respect catalog parameter.
12-02-04 - Version 3.1.5-gamma
- Fix comparisons made between string constants and dynamic strings that
are either toUpperCase()d or toLowerCase()d 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.
- Fixed BUG#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.
- 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()'.
- Handle case when string representation of timestamp contains trailing '.'
with no numbers following it.
- Fixed BUG#5706 - Inefficient detection of pre-existing string instances
in ResultSet.getNativeString().
- Don't throw exceptions for Connection.releaseSavepoint().
- Use a per-session Calendar instance by default when decoding dates
from ServerPreparedStatements (set to old, less performant behavior by
setting property 'dynamicCalendars=true').
- 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.
- Fixed BUG#5729 - UNSIGNED BIGINT unpacked incorrectly from
server-side prepared statement result sets.
- Fixed BUG#6225 - ServerSidePreparedStatement allocating short-lived
objects un-necessarily.
- Removed un-wanted 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.
- Fixed too-early creation of StringBuffer in EscapeProcessor.escapeSQL(),
also return String when escaping not needed (to avoid unnecssary object
allocations). Found while profiling for BUG#6359.
- Use null-safe-equals for key comparisons in updatable result sets.
- Fixed BUG#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).
- Use DatabaseMetaData.getIdentifierQuoteString() when building DBMD
queries.
- Use 1MB packet for sending file for LOAD DATA LOCAL INFILE if that
is < 'max_allowed_packet' on server.
- Fixed BUG#6399, ResultSetMetaData.getColumnDisplaySize() returns incorrect
values for multibyte charsets.
- Make auto-deserialization of java.lang.Objects stored in BLOBs
configurable via 'autoDeserialize' property (defaults to 'false').
- Re-work Field.isOpaqueBinary() to detect 'CHAR(n) CHARACTER SET BINARY'
to support fixed-length binary fields for ResultSet.getObject().
- Use our own implementation of buffered input streams to get around
blocking behavior of java.io.BufferedInputStream. Disable this with
'useReadAheadInput=false'.
- Fixed BUG#6348, 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().
09-04-04 - Version 3.1.4-beta
- Fixed BUG#4510 - connector/j 3.1.3 beta does not handle integers
correctly (caused by changes to support unsigned reads in
Buffer.readInt() -> Buffer.readShort()).
- Added support in DatabaseMetaData.getTables() and getTableTypes()
for VIEWs which are now available in MySQL server version 5.0.x.
- Fixed BUG#4642 -- ServerPreparedStatement.execute*() sometimes
threw ArrayIndexOutOfBoundsException when unpacking field metadata.
- Optimized integer number parsing, enable 'old' slower integer parsing
using JDK classes via 'useFastIntParsing=false' property.
- 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.
- Fixed BUG#4689 - ResultSet.wasNull() does not work for primatives if a
previous null was returned.
- Track packet sequence numbers if enablePacketDebug=true, and throw an
exception if packets received out-of-order.
- Fixed BUG#4482, ResultSet.getObject() returns wrong type for strings
when using prepared statements.
- Calling MysqlPooledConnection.close() twice (even though an application
error), caused NPE. Fixed.
- Fixed BUG#5012 -- ServerPreparedStatements dealing with return of
DECIMAL type don't work.
- Fixed BUG#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 obscurred test in getObject() for 'pseudo' bit type)
- 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'.
- The driver is more strict about truncation of numerics on
ResultSet.get*(), and will throw a 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).
- Added three ways to deal with all-zero datetimes when reading them from
a ResultSet, 'exception' (the default), which throws a SQLException
with a 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'.
- 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.
- 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.
07-07-04 - Version 3.1.3-beta
- Mangle output parameter names for CallableStatements so they
will not clash with user variable names.
- Added support for INOUT parameters in CallableStatements.
- Fix for BUG#4119, null bitmask sent for server-side prepared
statements was incorrect.
- Use SQL Standard SQL states by default, unless 'useSqlStateCodes'
property is set to 'false'.
- Added packet debuging code (see the 'enablePacketDebug' property
documentation).
- 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).
- Externalized more messages (on-going effort).
- Fix for BUG#4311 - Error in retrieval of mediumint column with
prepared statements and binary protocol.
- Support new timezone variables in MySQL-4.1.3 when
'useTimezone=true'
- 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.
06-09-04 - Version 3.1.2-alpha
- Fixed stored procedure parameter parsing info when size was
specified for a parameter (i.e. char(), varchar()).
- Enabled callable statement caching via 'cacheCallableStmts'
property.
- 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.
- Fixed case when no parameters could cause a NullPointerException
in CallableStatement.setOutputParameters().
- Removed wrapping of exceptions in MysqlIO.changeUser().
- 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 'gatherPerformanceMetrics' property, along with properties
to control when/where this info gets logged (see docs for more
info).
- ServerPreparedStatements weren't actually de-allocating
server-side resources when .close() was called.
- Added 'logSlowQueries' property, along with property
'slowQueriesThresholdMillis' to control when a query should
be considered 'slow'.
- Correctly map output parameters to position given in
prepareCall() vs. order implied during registerOutParameter() -
fixes BUG#3146.
- Correctly detect initial character set for servers >= 4.1.0
- Cleaned up detection of server properties.
- Support placeholder for parameter metadata for server >= 4.1.2
- Fix for BUG#3539 getProcedures() does not return any procedures in
result set
- Fix for BUG#3540 getProcedureColumns() doesn't work with wildcards
for procedure name
- Fixed BUG#3520 -- DBMD.getSQLStateType() returns incorrect value.
- Added 'connectionCollation' property to cause driver to issue
'set collation_connection=...' query on connection init if default
collation for given charset is not appropriate.
- Fixed DatabaseMetaData.getProcedures() when run on MySQL-5.0.0 (output of
'show procedure status' changed between 5.0.1 and 5.0.0.
- Fixed BUG#3804 -- getWarnings() returns SQLWarning instead of DataTruncation
- 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).
02-14-04 - Version 3.1.1-alpha
- Fixed bug with UpdatableResultSets not using client-side
prepared statements.
- Fixed character encoding issues when converting bytes to
ASCII when MySQL doesn't provide the character set, and
the JVM is set to a multibyte encoding (usually affecting
retrieval of numeric values).
- Unpack 'unknown' data types from server prepared statements
as Strings.
- Implemented long data (Blobs, Clobs, InputStreams, Readers)
for server prepared statements.
- Implemented Statement.getWarnings() for MySQL-4.1 and newer
(using 'SHOW WARNINGS').
- Default result set type changed to TYPE_FORWARD_ONLY
(JDBC compliance).
- Centralized setting of result set type and concurrency.
- Re-factored how connection properties are set and exposed
as DriverPropertyInfo as well as Connection and DataSource
properties.
- Support for NIO. Use 'useNIO=true' on platforms that support
NIO.
- Support for SAVEPOINTs (MySQL >= 4.0.14 or 4.1.1).
- Support for mysql_change_user()...See the changeUser() method
in com.mysql.jdbc.Connection.
- 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.
- Ensure that warnings are cleared before executing queries
on prepared statements, as-per JDBC spec (now that we support
warnings).
- Support 'old' profileSql capitalization in ConnectionProperties.
This property is deprecated, you should use 'profileSQL' if possible.
- Optimized Buffer.readLenByteArray() to return shared empty byte array
when length is 0.
- Allow contents of PreparedStatement.setBlob() to be retained
between calls to .execute*().
- Deal with 0-length tokens in EscapeProcessor (caused by callable
statement escape syntax).
- Check for closed connection on delete/update/insert row operations in
UpdatableResultSet.
- Fix support for table aliases when checking for all primary keys in
UpdatableResultSet.
- Removed useFastDates connection property.
- Correctly initialize datasource properties from JNDI Refs, including
explicitly specified URLs.
- DatabaseMetaData now reports supportsStoredProcedures() for
MySQL versions >= 5.0.0
- Fixed stack overflow in Connection.prepareCall() (bad merge).
- Fixed IllegalAccessError to Calendar.getTimeInMillis() in DateTimeValue
(for JDK < 1.4).
- Fix for BUG#1673, where DatabaseMetaData.getColumns() is not
returning correct column ordinal info for non '%' column name patterns.
- Merged fix of datatype mapping from MySQL type 'FLOAT' to
java.sql.Types.REAL from 3.0 branch.
- Detect collation of column for RSMD.isCaseSensitive().
- Fixed sending of queries > 16M.
- Added named and indexed input/output parameter support to CallableStatement.
MySQL-5.0.x or newer.
- Fixed NullPointerException in ServerPreparedStatement.setTimestamp(),
as well as year and month descrepencies in
ServerPreparedStatement.setTimestamp(), setDate().
- Added ability to have multiple database/JVM targets for compliance
and regression/unit tests in build.xml.
- Fixed NPE and year/month bad conversions when accessing some
datetime functionality in ServerPreparedStatements and their
resultant result sets.
- Display where/why a connection was implicitly closed (to
aid debugging).
- CommunicationsException implemented, that tries to determine
why communications was lost with a server, and displays
possible reasons when .getMessage() is called.
- Fixed BUG#2359, NULL values for numeric types in binary
encoded result sets causing NullPointerExceptions.
- Implemented Connection.prepareCall(), and DatabaseMetaData.
getProcedures() and getProcedureColumns().
- Reset 'long binary' parameters in ServerPreparedStatement when
clearParameters() is called, by sending COM_RESET_STMT to the
server.
- Merged prepared statement caching, and .getMetaData() support
from 3.0 branch.
- Fixed off-by-1900 error in some cases for
years in TimeUtil.fastDate/TimeCreate() when unpacking results
from server-side prepared statements.
- Fixed BUG#2502 -- charset conversion issue in getTables().
- Implemented multiple result sets returned from a statement
or stored procedure.
- Fixed BUG#2606 -- Server side prepared statements not returning
datatype 'YEAR' correctly.
- Enabled streaming of result sets from server-side prepared
statements.
- Fixed BUG#2623 -- Class-cast exception when using
scrolling result sets and server-side prepared statements.
- Merged unbuffered input code from 3.0.
- Fixed ConnectionProperties that weren't properly exposed
via accessors, cleaned up ConnectionProperties code.
- Fixed BUG#2671, NULL fields not being encoded correctly in
all cases in server side prepared statements.
- Fixed rare buffer underflow when writing numbers into buffers
for sending prepared statement execution requests.
- Use DocBook version of docs for shipped versions of drivers.
02-18-03 - Version 3.1.0-alpha
- Added 'requireSSL' property.
- 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.
- Track open Statements, close all when Connection.close()
is called (JDBC compliance).
06-23-05 - Version 3.0.17-ga
- Fixed BUG#5874, Timestamp/Time conversion goes in the wrong 'direction'
when useTimeZone='true' and server timezone differs from client timezone.
- Fixed BUG#7081, DatabaseMetaData.getIndexInfo() ignoring 'unique'
parameter.
- Support new protocol type 'MYSQL_TYPE_VARCHAR'.
- Added 'useOldUTF8Behavoior' 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.
- Fixed BUG#7316 - Statements created from a pooled connection were
returning physical connection instead of logical connection when
getConnection() was called.
- Fixed BUG#7033 - PreparedStatements don't encode Big5 (and other
multibyte) character sets correctly in static SQL strings.
- Fixed BUG#6966, connections starting up failed-over (due to down master)
never retry master.
- Fixed BUG#7061, PreparedStatement.fixDecimalExponent() adding extra
'+', making number unparseable by MySQL server.
- Fixed BUG#7686, Timestamp key column data needed "_binary'" stripped for
UpdatableResultSet.refreshRow().
- 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).
- Fixed BUG#7601, PreparedStatement.fixDecimalExponent() adding extra
'+', making number unparseable by MySQL server.
- Escape sequence {fn convert(..., type)} now supports ODBC-style types
that are prepended by 'SQL_'.
- Fixed duplicated code in configureClientCharset() that prevented
useOldUTF8Behavior=true from working properly.
- Handle streaming result sets with > 2 billion rows properly by fixing
wraparound of row number counter.
- Fixed BUG#7607 - MS932, SHIFT_JIS and Windows_31J not recog. as
aliases for sjis.
- Fixed BUG#6549 (while fixing #7607), adding 'CP943' to aliases for
sjis.
- Fixed BUG#8064, which requires hex escaping of binary data when using
multibyte charsets with prepared statements.
- Fixed BUG#8812, NON_UNIQUE column from DBMD.getIndexInfo() returned
inverted value.
- Workaround for server BUG#9098 - default values of CURRENT_* for
DATE/TIME/TIMESTAMP/TIMESTAMP columns can't be distinguished from
'string' values, so UpdatableResultSet.moveToInsertRow() generates
bad SQL for inserting default values.
- Fixed BUG#8629 - 'EUCKR' charset is sent as 'SET NAMES euc_kr' which
MySQL-4.1 and newer doesn't understand.
- DatabaseMetaData.supportsSelectForUpdate() returns correct value based
on server version.
- Use hex escapes for PreparedStatement.setBytes() for double-byte charsets
including 'aliases' Windows-31J, CP934, MS932.
- 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.
11-15-04 - Version 3.0.16-ga
- Re-issue character set configuration commands when re-using pooled
connections and/or Connection.changeUser() when connected to MySQL-4.1
or newer.
- 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.
- Fixed BUG#5664, ResultSet.updateByte() when on insert row
throws ArrayOutOfBoundsException.
- Fixed DatabaseMetaData.getTypes() returning incorrect (i.e. non-negative)
scale for the 'NUMERIC' type.
- Fixed BUG#6198, off-by-one bug in Buffer.readString(string).
- Made TINYINT(1) -> BIT/Boolean conversion configurable via 'tinyInt1isBit'
property (default 'true' to be JDBC compliant out of the box).
- Only set 'character_set_results' during connection establishment if
server version >= 4.1.1.
- Fixed regression where useUnbufferedInput was defaulting to 'false'.
- Fixed BUG#6231, ResultSet.getTimestamp() on a column with TIME in it
fails.
09-04-04 - Version 3.0.15-production
- Fixed BUG#4010 - StringUtils.escapeEasternUnicodeByteStream is still
broken for GBK
- Fixed BUG#4334 - Failover for autoReconnect not using port #'s for any
hosts, and not retrying all hosts. (WARN: 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.
- 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().
- Removed redundant calls to checkRowPos() in ResultSet.
- Fixed BUG#4742, 'DOUBLE' mapped twice in DBMD.getTypeInfo().
- Added FLOSS license exemption.
- Fixed BUG#4808, calling .close() twice on a PooledConnection causes NPE.
- Fixed BUG#4138 and BUG#4860, 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.
- 'Production' - 'GA' in naming scheme of distributions.
- Fix for BUG#4880, 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).
- Fixed BUG#5022 - ResultSet should release Field[] instance in .close().
- Fixed BUG#5069 -- ResultSet.getMetaData() should not return
incorrectly-initialized metadata if the result set has been closed, but
should instead throw a SQLException. Also fixed for getRow() and
getWarnings() and traversal methods by calling checkClosed() before
operating on instance-level fields that are nullified during .close().
- Parse new timezone variables from 4.1.x servers.
- Use _binary introducer for PreparedStatement.setBytes() and
set*Stream() when connected to MySQL-4.1.x or newer to avoid
misinterpretation during character conversion.
05-28-04 - Version 3.0.14-production
- Fixed URL parsing error
05-27-04 - Version 3.0.13-production
- Fixed BUG#3848 - Using a MySQLDatasource without server name fails
- Fixed BUG#3920 - "No Database Selected" when using
MysqlConnectionPoolDataSource.
- Fixed BUG#3873 - PreparedStatement.getGeneratedKeys() method returns only
1 result for batched insertions
05-18-04 - Version 3.0.12-production
- Add unsigned attribute to DatabaseMetaData.getColumns() output
in the TYPE_NAME column.
- Added 'failOverReadOnly' property, to allow end-user to configure
state of connection (read-only/writable) when failed over.
- 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.
- Don't escape SJIS/GBK/BIG5 when using MySQL-4.1 or newer.
- Allow 'url' parameter for MysqlDataSource and MysqlConnectionPool
DataSource so that passing of other properties is possible from
inside appservers.
- Map duplicate key and foreign key errors to SQLState of
'23000'.
- Backport documentation tooling from 3.1 branch.
- Return creating statement for ResultSets created by
getGeneratedKeys() (BUG#2957)
- Allow java.util.Date to be sent in as parameter to
PreparedStatement.setObject(), converting it to a Timestamp
to maintain full precision (BUG#3103).
- Don't truncate BLOBs/CLOBs when using setBytes() and/or
setBinary/CharacterStream() (BUG#2670).
- Dynamically configure character set mappings for field-level
character sets on MySQL-4.1.0 and newer using 'SHOW COLLATION'
when connecting.
- Map 'binary' character set to 'US-ASCII' to support DATETIME
charset recognition for servers >= 4.1.2
- Use 'SET character_set_results" during initialization to allow any
charset to be returned to the driver for result sets.
- Use charsetnr returned during connect to encode queries before
issuing 'SET NAMES' on MySQL >= 4.1.0.
- 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.
- Only set character_set_results for MySQL >= 4.1.0.
- Fixed BUG#3511, StringUtils.escapeSJISByteStream() not covering all
eastern double-byte charsets correctly.
- Renamed StringUtils.escapeSJISByteStream() to more appropriate
escapeEasternUnicodeByteStream().
- Fixed BUG#3554 - Not specifying database in URL caused MalformedURL
exception.
- Auto-convert MySQL encoding names to Java encoding names if used
for characterEncoding property.
- Added encoding names that are recognized on some JVMs to fix case
where they were reverse-mapped to MySQL encoding names incorrectly.
- Use junit.textui.TestRunner for all unit tests (to allow them to be
run from the command line outside of Ant or Eclipse).
- Fixed BUG#3557 - UpdatableResultSet not picking up default values
for moveToInsertRow().
- Fixed BUG#3570 - inconsistent reporting of column type. The server
still doesn't return all types for *BLOBs *TEXT correctly, so the
driver won't return those correctly.
- Fixed BUG#3520 -- DBMD.getSQLStateType() returns incorrect value.
- Fixed regression in PreparedStatement.setString() and eastern character
encodings.
- Made StringRegressionTest 4.1-unicode aware.
02-19-04 - Version 3.0.11-stable
- 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.
- AutoReconnect time was growing faster than exponentially (BUG#2447).
- Fixed failover always going to last host in list (BUG#2578)
- Added 'useUnbufferedInput' parameter, and now use it by default
(due to JVM issue
http://developer.java.sun.com/developer/bugParade/bugs/4401235.html)
- Detect 'on/off' or '1','2','3' form of lower_case_table_names on
server.
- Return 'java.lang.Integer' for TINYINT and SMALLINT types from
ResultSetMetaData.getColumnClassName() (fix for BUG#2852).
- Return 'java.lang.Double' for FLOAT type from ResultSetMetaData.
getColumnClassName() (fix for BUG#2855).
- Return '[B' instead of java.lang.Object for BINARY, VARBINARY and
LONGVARBINARY types from ResultSetMetaData.getColumnClassName()
(JDBC compliance).
- Issue connection events on all instances created from a
ConnectionPoolDataSource.
01-13-04 - Version 3.0.10-stable
- Don't count quoted id's when inside a 'string' in PreparedStatement
parsing (fix for BUG#1511).
- 'Friendlier' exception message for PacketTooLargeException
(BUG#1534).
- Backported fix for aliased tables and UpdatableResultSets in
checkUpdatability() method from 3.1 branch.
- Fix for ArrayIndexOutOfBounds exception when using Statement.setMaxRows()
(BUG#1695).
- Fixed BUG#1576, dealing with large blobs and split packets not being
read correctly.
- Fixed regression of Statement.getGeneratedKeys() and REPLACE statements.
- Fixed BUG#1630, subsequent call to ResultSet.updateFoo() causes NPE if
result set is not updatable.
- Fix for 4.1.1-style auth with no password.
- Fix for BUG#1731, Foreign Keys column sequence is not consistent in
DatabaseMetaData.getImported/Exported/CrossReference().
- Fix for BUG#1775 - DatabaseMetaData.getSystemFunction() returning
bad function 'VResultsSion'.
- Fix for BUG#1592 -- cross-database updatable result sets
are not checked for updatability correctly.
- DatabaseMetaData.getColumns() should return Types.LONGVARCHAR for
MySQL LONGTEXT type.
- ResultSet.getObject() on TINYINT and SMALLINT columns should return
Java type 'Integer' (BUG#1913)
- Added 'alwaysClearStream' connection property, which causes the driver
to always empty any remaining data on the input stream before
each query.
- Added more descriptive error message 'Server Configuration Denies
Access to DataSource', as well as retrieval of message from server.
- Autoreconnect code didn't set catalog upon reconnect if it had been
changed.
- Implement ResultSet.updateClob().
- ResultSetMetaData.isCaseSensitive() returned wrong value for CHAR/VARCHAR
columns.
- Fix for BUG#1933 -- Connection property "maxRows" not honored.
- Fix for BUG#1925 -- Statements being created too many times in
DBMD.extractForeignKeyFromCreateTable().
- Fix for BUG#1914 -- Support escape sequence {fn convert ... }
- Fix for BUG#1958 -- ArrayIndexOutOfBounds when parameter number ==
number of parameters + 1.
- Fix for BUG#2006 -- ResultSet.findColumn() should use first matching
column name when there are duplicate column names in SELECT query
(JDBC-compliance).
- Removed static synchronization bottleneck from
PreparedStatement.setTimestamp().
- Removed static synchronization bottleneck from instance factory
method of SingleByteCharsetConverter.
- Enable caching of the parsing stage of prepared statements via
the 'cachePrepStmts', 'prepStmtCacheSize' and 'prepStmtCacheSqlLimit'
properties (disabled by default).
- Speed up parsing of PreparedStatements, try to use one-pass whenever
possible.
- Fixed security exception when used in Applets (applets can't
read the system property 'file.encoding' which is needed
for LOAD DATA LOCAL INFILE).
- Use constants for SQLStates.
- Map charset 'ko18_ru' to 'ko18r' when connected to MySQL-4.1.0 or
newer.
- Ensure that Buffer.writeString() saves room for the \0.
- Fixed exception 'Unknown character set 'danish' on connect w/ JDK-1.4.0
- Fixed mappings in SQLError to report deadlocks with SQLStates of '41000'.
- '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.
10-07-03 - Version 3.0.9-stable
- 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().
- Fixed ResultSet.previous() behavior to move current
position to before result set when on first row
of result set (bugs.mysql.com BUG#496)
- Fixed Statement and PreparedStatement issuing bogus queries
when setMaxRows() had been used and a LIMIT clause was present
in the query.
- Fixed BUG#661 - refreshRow didn't work when primary key values
contained values that needed to be escaped (they ended up being
doubly-escaped).
- Support InnoDB contraint names when extracting foreign key info
in DatabaseMetaData BUG#517 and BUG#664
(impl. ideas from Parwinder Sekhon)
- Backported 4.1 protocol changes from 3.1 branch (server-side SQL
states, new field info, larger client capability flags,
connect-with-database, etc).
- Fix UpdatableResultSet to return values for getXXX() when on
insert row (BUG#675).
- The insertRow in an UpdatableResultSet is now loaded with
the default column values when moveToInsertRow() is called
(BUG#688)
- DatabaseMetaData.getColumns() wasn't returning NULL for
default values that are specified as NULL.
- Change default statement type/concurrency to TYPE_FORWARD_ONLY
and CONCUR_READ_ONLY (spec compliance).
- Don't try and reset isolation level on reconnect if MySQL doesn't
support them.
- Don't wrap SQLExceptions in RowDataDynamic.
- Don't change timestamp TZ twice if useTimezone==true (BUG#774)
- Fixed regression in large split-packet handling (BUG#848).
- Better diagnostic error messages in exceptions for 'streaming'
result sets.
- Issue exception on ResultSet.getXXX() on empty result set (wasn't
caught in some cases).
- Don't hide messages from exceptions thrown in I/O layers.
- Don't fire connection closed events when closing pooled connections, or
on PooledConnection.getConnection() with already open connections (BUG#884).
- 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.
- Fix for BUG#879, double-escaping of '\' when charset is SJIS or GBK and '\'
appears in non-escaped input.
- 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.
- Fixed BUG#1099, DatabaseMetaData.getColumns() getting confused about the
keyword 'set' in character columns.
- Fixed deadlock issue with Statement.setMaxRows().
- Fixed CLOB.truncate(), BUG#1130
- Optimized CLOB.setChracterStream(), BUG#1131
- Made databaseName, portNumber and serverName optional parameters
for MysqlDataSourceFactory (BUG#1246)
- Fix for BUG#1247 -- ResultSet.get/setString mashing char 127
- Backported auth. changes for 4.1.1 and newer from 3.1 branch.
- Added com.mysql.jdbc.util.BaseBugReport to help creation of testcases
for bug reports.
- 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.
05-23-03 - Version 3.0.8-stable
- Allow bogus URLs in Driver.getPropertyInfo().
- Return list of generated keys when using multi-value INSERTS
with Statement.getGeneratedKeys().
- 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.
- Unicode character 0xFFFF in a string would cause the driver to
throw an ArrayOutOfBoundsException (Bug #378)
- Return correct amount of generated keys when using 'REPLACE'
statements.
- Fix problem detecting server character set in some cases.
- Fix row data decoding error when using _very_ large packets.
- Optimized row data decoding.
- Issue exception when operating on an already-closed
prepared statement.
- Fixed SJIS encoding bug, thanks to Naoto Sato.
- Optimized usage of EscapeProcessor.
- Allow multiple calls to Statement.close()
04-08-03 - Version 3.0.7-stable
- Fixed MysqlPooledConnection.close() calling wrong event type.
- Fixed StringIndexOutOfBoundsException in PreparedStatement.
setClob().
- 4.1 Column Metadata fixes
- Remove synchronization from Driver.connect() and
Driver.acceptsUrl().
- IOExceptions during a transaction now cause the Connection to
be closed.
- Fixed missing conversion for 'YEAR' type in ResultSetMetaData.
getColumnTypeName().
- Don't pick up indexes that start with 'pri' as primary keys
for DBMD.getPrimaryKeys().
- Throw SQLExceptions when trying to do operations on a forcefully
closed Connection (i.e. when a communication link failure occurs).
- You can now toggle profiling on/off using
Connection.setProfileSql(boolean).
- Fixed charset issues with database metadata (charset was not
getting set correctly).
- 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.
- Fixed escaping of 0x5c ('\') character for GBK and Big5 charsets.
- Fixed ResultSet.getTimestamp() when underlying field is of type DATE.
- Ensure that packet size from alignPacketSize() does not
exceed MAX_ALLOWED_PACKET (JVM bug)
- Don't reset Connection.isReadOnly() when autoReconnecting.
02-18-03 - Version 3.0.6-stable
- Fixed ResultSetMetaData to return "" when catalog not known.
Fixes NullPointerExceptions with Sun's CachedRowSet.
- Fixed DBMD.getTypeInfo() and DBMD.getColumns() returning
different value for precision in TEXT/BLOB types.
- Allow ignoring of warning for 'non transactional tables' during
rollback (compliance/usability) by setting 'ignoreNonTxTables'
property to 'true'.
- Fixed SQLExceptions getting swallowed on initial connect.
- Fixed Statement.setMaxRows() to stop sending 'LIMIT' type queries
when not needed (performance)
- Clean up Statement query/method mismatch tests (i.e. INSERT not
allowed with .executeQuery()).
- More checks added in ResultSet traversal method to catch
when in closed state.
- Fixed ResultSetMetaData.isWritable() to return correct value.
- Add 'window' of different NULL sorting behavior to
DBMD.nullsAreSortedAtStart (4.0.2 to 4.0.10, true, otherwise,
no).
- Implemented Blob.setBytes(). You still need to pass the
resultant Blob back into an updatable ResultSet or
PreparedStatement to persist the changes, as MySQL does
not support 'locators'.
- Backported 4.1 charset field info changes from Connector/J 3.1
01-22-03 - Version 3.0.5-gamma
- Fixed Buffer.fastSkipLenString() causing ArrayIndexOutOfBounds
exceptions with some queries when unpacking fields.
- Implemented an empty TypeMap for Connection.getTypeMap() so that
some third-party apps work with MySQL (IBM WebSphere 5.0 Connection
pool).
- Added missing LONGTEXT type to DBMD.getColumns().
- Retrieve TX_ISOLATION from database for
Connection.getTransactionIsolation() when the MySQL version
supports it, instead of an instance variable.
- Quote table names in DatabaseMetaData.getColumns(),
getPrimaryKeys(), getIndexInfo(), getBestRowIdentifier()
- Greatly reduce memory required for setBinaryStream() in
PreparedStatements.
- Fixed ResultSet.isBeforeFirst() for empty result sets.
- Added update options for foreign key metadata.
01-06-03 - Version 3.0.4-gamma
- Added quoted identifiers to database names for
Connection.setCatalog.
- Added support for quoted identifiers in PreparedStatement
parser.
- Streamlined character conversion and byte[] handling in
PreparedStatements for setByte().
- 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 SELECTs on tables with primary keys and
that you have selected all primary keys in your query.
- Added support for 4.0.8-style large packets.
- Fixed PreparedStatement.executeBatch() parameter overwriting.
12-17-02 - Version 3.0.3-dev
- Changed charsToByte in SingleByteCharConverter to be non-static
- Changed SingleByteCharConverter to use lazy initialization of each
converter.
- Fixed charset handling in Fields.java
- Implemented Connection.nativeSQL()
- More robust escape tokenizer -- recognize '--' comments, and allow
nested escape sequences (see testsuite.EscapeProcessingTest)
- DBMD.getImported/ExportedKeys() now handles multiple foreign keys
per table.
- Fixed ResultSetMetaData.getPrecision() returning incorrect values
for some floating point types.
- Fixed ResultSetMetaData.getColumnTypeName() returning BLOB for
TEXT and TEXT for BLOB types.
- Fixed Buffer.isLastDataPacket() for 4.1 and newer servers.
- Added CLIENT_LONG_FLAG to be able to get more column flags
(isAutoIncrement() being the most important)
- Because of above, implemented ResultSetMetaData.isAutoIncrement()
to use Field.isAutoIncrement().
- Honor 'lower_case_table_names' when enabled in the server when
doing table name comparisons in DatabaseMetaData methods.
- Some MySQL-4.1 protocol support (extended field info from selects)
- Use non-aliased table/column names and database names to fullly
qualify tables and columns in UpdatableResultSet (requires
MySQL-4.1 or newer)
- Allow user to alter behavior of Statement/
PreparedStatement.executeBatch() via 'continueBatchOnError' property
(defaults to 'true').
- Check for connection closed in more Connection methods
(createStatement, prepareStatement, setTransactionIsolation,
setAutoCommit).
- More robust implementation of updatable result sets. Checks that
_all_ primary keys of the table have been selected.
- '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).
- Substitute '?' for unknown character conversions in single-byte
character sets instead of '\0'.
- NamedPipeSocketFactory now works (only intended for Windows), see
README for instructions.
11-08-02 - Version 3.0.2-dev
- Fixed issue with updatable result sets and PreparedStatements not
working
- Fixed ResultSet.setFetchDirection(FETCH_UNKNOWN)
- Fixed issue when calling Statement.setFetchSize() when using
arbitrary values
- Fixed incorrect conversion in ResultSet.getLong()
- Implemented ResultSet.updateBlob().
- 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 various non-ASCII character encoding issues.
- Added driver property 'useHostsInPrivileges'. Defaults to true.
Affects whether or not '@hostname' will be used in
DBMD.getColumn/TablePrivileges.
- All DBMD result set columns describing schemas now return NULL
to be more compliant with the behavior of other JDBC drivers
for other databases (MySQL does not support schemas).
- Added SSL support. See README for information on how to use it.
- Properly restore connection properties when autoReconnecting
or failing-over, including autoCommit state, and isolation level.
- Use 'SHOW CREATE TABLE' when possible for determining foreign key
information for DatabaseMetaData...also allows cascade options for
DELETE information to be returned
- Escape 0x5c character in strings for the SJIS charset.
- Fixed start position off-by-1 error in Clob.getSubString()
- Implemented Clob.truncate()
- Implemented Clob.setString()
- Implemented Clob.setAsciiStream()
- Implemented Clob.setCharacterStream()
- Added com.mysql.jdbc.MiniAdmin class, which allows you to send
'shutdown' command to MySQL server...Intended to be used when 'embedding'
Java and MySQL server together in an end-user application.
- Added 'connectTimeout' parameter that allows users of JDK-1.4 and newer
to specify a maxium time to wait to establish a connection.
- Failover and autoReconnect only work when the connection is in a
autoCommit(false) state, in order to stay transaction safe
- Added 'queriesBeforeRetryMaster' property that specifies how many
queries to issue when failed over before attempting to reconnect
to the master (defaults to 50)
- Fixed DBMD.supportsResultSetConcurrency() so that it returns true
for ResultSet.TYPE_SCROLL_INSENSITIVE and ResultSet.CONCUR_READ_ONLY or
ResultSet.CONCUR_UPDATABLE
- Fixed ResultSet.isLast() for empty result sets (should return false).
- PreparedStatement now honors stream lengths in setBinary/Ascii/Character
Stream() unless you set the connection property
'useStreamLengthsInPrepStmts' to 'false'.
- Removed some not-needed temporary object creation by using Strings
smarter in EscapeProcessor, Connection and DatabaseMetaData classes.
09-21-02 - Version 3.0.1-dev
- Fixed ResultSet.getRow() off-by-one bug.
- Fixed RowDataStatic.getAt() off-by-one bug.
- Added limited Clob functionality (ResultSet.getClob(),
PreparedStatemtent.setClob(),
PreparedStatement.setObject(Clob).
- Added socketTimeout parameter to URL.
- Connection.isClosed() no longer "pings" the server.
- Connection.close() issues rollback() when getAutoCommit() == false
- Added "paranoid" parameter...sanitizes error messages removing
"sensitive" information from them (i.e. hostnames, ports,
usernames, etc.), as well as clearing "sensitive" data structures
when possible.
- Fixed ResultSetMetaData.isSigned() for TINYINT and BIGINT.
- Charsets now automatically detected. Optimized code for single-byte
character set conversion.
- Implemented ResultSet.getCharacterStream()
- Added "LOCAL TEMPORARY" to table types in DatabaseMetaData.getTableTypes()
- Massive code clean-up to follow Java coding conventions (the time had come)
07-31-02 - Version 3.0.0-dev
- !!! LICENSE CHANGE !!! The driver is now GPL. If you need
non-GPL licenses, please contact me <mark@mysql.com>
- JDBC-3.0 functionality including
Statement/PreparedStatement.getGeneratedKeys() and
ResultSet.getURL()
- Performance enchancements - driver is now 50-100% faster
in most situations, and creates fewer temporary objects
- Repackaging...new driver name is "com.mysql.jdbc.Driver",
old name still works, though (the driver is now provided
by MySQL-AB)
- Better checking for closed connections in Statement
and PreparedStatement.
- Support for streaming (row-by-row) result sets (see README)
Thanks to Doron.
- Support for large packets (new addition to MySQL-4.0 protocol),
see README for more information.
- JDBC Compliance -- Passes all tests besides stored procedure tests
- Fix and sort primary key names in DBMetaData (SF bugs 582086 and 582086)
- Float types now reported as java.sql.Types.FLOAT (SF bug 579573)
- ResultSet.getTimestamp() now works for DATE types (SF bug 559134)
- ResultSet.getDate/Time/Timestamp now recognizes all forms of invalid
values that have been set to all zeroes by MySQL (SF bug 586058)
- Testsuite now uses Junit (which you can get from www.junit.org)
- The driver now only works with JDK-1.2 or newer.
- Added multi-host failover support (see README)
- General source-code cleanup.
- Overall speed improvements via controlling transient object
creation in MysqlIO class when reading packets
- Performance improvements in string handling and field
metadata creation (lazily instantiated) contributed by
Alex Twisleton-Wykeham-Fiennes
05-16-02 - Version 2.0.14
- More code cleanup
- PreparedStatement now releases resources on .close() (SF bug 553268)
- Quoted identifiers not used if server version does not support them. Also,
if server started with --ansi or --sql-mode=ANSI_QUOTES then '"' will be
used as an identifier quote, otherwise '`' will be used.
- ResultSet.getDouble() now uses code built into JDK to be more precise (but slower)
- LogicalHandle.isClosed() calls through to physical connection
- Added SQL profiling (to STDERR). Set "profileSql=true" in your JDBC url.
See README for more information.
- Fixed typo for relaxAutoCommit parameter.
04-24-02 - Version 2.0.13
- More code cleanup.
- Fixed unicode chars being read incorrectly (SF bug 541088)
- Faster blob escaping for PrepStmt
- Added set/getPortNumber() to DataSource(s) (SF bug 548167)
- Added setURL() to MySQLXADataSource (SF bug 546019)
- PreparedStatement.toString() fixed (SF bug 534026)
- ResultSetMetaData.getColumnClassName() now implemented
- 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)
04-07-02 - Version 2.0.12
- General code cleanup.
- Added getIdleFor() method to Connection and MysqlLogicalHandle.
- Relaxed synchronization in all classes, should fix 520615 and 520393.
- Added getTable/ColumnPrivileges() to DBMD (fixes 484502).
- Added new types to getTypeInfo(), fixed existing types thanks to
Al Davis and Kid Kalanon.
- Added support for BIT types (51870) to PreparedStatement.
- Fixed getRow() bug (527165) in ResultSet
- Fixes for ResultSet updatability in PreparedStatement.
- Fixed timezone off by 1-hour bug in PreparedStatement (538286, 528785).
- ResultSet: Fixed updatability (values being set to null
if not updated).
- DataSources - fixed setUrl bug (511614, 525565),
wrong datasource class name (532816, 528767)
- Added identifier quoting to all DatabaseMetaData methods
that need them (should fix 518108)
- Added support for YEAR type (533556)
- 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.
- ResultSet.refreshRow() implemented.
- Fixed testsuite.Traversal afterLast() bug, thanks to Igor Lastric.
01-27-02 - Version 2.0.11
- Fixed missing DELETE_RULE value in
DBMD.getImported/ExportedKeys() and getCrossReference().
- Full synchronization of Statement.java.
- More changes to fix "Unexpected end of input stream"
errors when reading BLOBs. This should be the last fix.
01-24-02 - Version 2.0.10
- Fixed spurious "Unexpected end of input stream" errors in
MysqlIO (bug 507456).
- Fixed null-pointer-exceptions when using
MysqlConnectionPoolDataSource with Websphere 4 (bug 505839).
01-13-02 - Version 2.0.9
- Ant build was corrupting included jar files, fixed
(bug 487669).
- Fixed extra memory allocation in MysqlIO.readPacket()
(bug 488663).
- Implementation of DatabaseMetaData.getExported/ImportedKeys() and
getCrossReference().
- 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)
- 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).
- Added detection of network connection being closed when reading packets
(thanks to Todd Lizambri).
- Fixed quoting error with escape processor (bug 486265).
- Report batch update support through DatabaseMetaData (bug 495101).
- Fixed off-by-one-hour error in PreparedStatement.setTimestamp()
(bug 491577).
- 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)
- Fixed casting bug in PreparedStatement (bug 488663).
11-25-01 - Version 2.0.8
- Batch updates now supported (thanks to some inspiration
from Daniel Rall).
- XADataSource/ConnectionPoolDataSource code (experimental)
- PreparedStatement.setAnyNumericType() now handles positive
exponents correctly (adds "+" so MySQL can understand it).
- 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).
10-24-01 - Version 2.0.7
- PreparedStatement.setCharacterStream() now implemented
- Fixed dangling socket problem when in high availability
(autoReconnect=true) mode, and finalizer for Connection will
close any dangling sockets on GC.
- Fixed ResultSetMetaData.getPrecision() returning one
less than actual on newer versions of MySQL.
- ResultSet.getBlob() now returns null if column value
was null.
- 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 DatabaseMetaData.supportsTransactions(), and
supportsTransactionIsolationLevel() and getTypeInfo()
SQL_DATETIME_SUB and SQL_DATA_TYPE fields not being
readable.
- Fixed PreparedStatement generating SQL that would end
up with syntax errors for some queries.
- Fixed ResultSet.isAfterLast() always returning false.
- Fixed timezone issue in PreparedStatement.setTimestamp()
(thanks to Erik Olofsson)
- Captialize type names when "captializeTypeNames=true"
is passed in URL or properties (for WebObjects, thanks
to Anjo Krank)
- Updatable result sets now correctly handle NULL
values in fields.
- PreparedStatement.setDouble() now uses full-precision
doubles (reverting a fix made earlier to truncate them).
- PreparedStatement.setBoolean() will use 1/0 for values
if your MySQL Version >= 3.21.23.
06-16-01 - Version 2.0.6
- Fixed PreparedStatement parameter checking
- Fixed case-sensitive column names in ResultSet.java
06-13-01 - Version 2.0.5
- Fixed ResultSet.getBlob() ArrayIndex out-of-bounds
- Fixed ResultSetMetaData.getColumnTypeName for TEXT/BLOB
- Fixed ArrayIndexOutOfBounds when sending large BLOB queries
(Max size packet was not being set)
- Added ISOLATION level support to Connection.setIsolationLevel()
- Fixed NPE on PreparedStatement.executeUpdate() when all columns
have not been set.
- Fixed data parsing of TIMESTAMPs with 2-digit years
- Added Byte to PreparedStatement.setObject()
- ResultSet.getBoolean() now recognizes '-1' as 'true'
- ResultSet has +/-Inf/inf support
- ResultSet.insertRow() works now, even if not all columns are
set (they will be set to "NULL")
- DataBaseMetaData.getCrossReference() no longer ArrayIndexOOB
- getObject() on ResultSet correctly does TINYINT->Byte and
SMALLINT->Short
12-03-00 - Version 2.0.3
- Implemented getBigDecimal() without scale component
for JDBC2.
- Fixed composite key problem with updateable result sets.
- Added detection of -/+INF for doubles.
- Faster ASCII string operations.
- Fixed incorrect detection of MAX_ALLOWED_PACKET, so sending
large blobs should work now.
- Fixed off-by-one error in java.sql.Blob implementation code.
- Added "ultraDevHack" URL parameter, set to "true" to allow
(broken) Macromedia UltraDev to use the driver.
04-06-00 - Version 2.0.1
- Fixed RSMD.isWritable() returning wrong value.
Thanks to Moritz Maass.
- Cleaned up exception handling when driver connects
- Columns that are of type TEXT now return as Strings
when you use getObject()
- DatabaseMetaData.getPrimaryKeys() now works correctly wrt
to key_seq. Thanks to Brian Slesinsky.
- No escape processing is done on PreparedStatements anymore
per JDBC spec.
- Fixed many JDBC-2.0 traversal, positioning bugs, especially
wrt to empty result sets. Thanks to Ron Smits, Nick Brook,
Cessar Garcia and Carlos Martinez.
- Fixed some issues with updatability support in ResultSet when
using multiple primary keys.
02-21-00 - Version 2.0pre5
- Fixed Bad Handshake problem.
01-10-00 - Version 2.0pre4
- 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 wrt. to packet sizing when reading from
the server and when alloc'ing to write to the server.
08-17-99 - Version 2.0pre
- 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)
07-04-99 - Version 1.2b
- 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.
04-14-99 - Version 1.2a
- 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)
03-24-99 - Version 1.1i
- Fixed Timestamps for PreparedStatements
- Fixed null pointer exceptions in RSMD and RS
- Re-compiled with jikes for valid class files (thanks ms!)
03-08-99 - Version 1.1h
- Fixed escape processor to deal with un-matched { 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)
02-19-99 - Version 1.1g
- 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 un-touched to the MySQL server.
- Fixes to getDriverPropertyInfo().
12-31-98 - Version 1.1f
- 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)
11-03-98 - Version 1.1b
- 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.
9-02-98 - Vesion 1.1
- 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, e.g. 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.
8-24-98 - Version 1.0
- 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=... etc).
8-04-98 - Version 0.9d
- 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, etc.
- 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.
7-28-98 - Version 0.9
- 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.
7-06-98 - Version 0.8
- 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.
7-01-98 - Version 0.7
- 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.
5-21-98 - Version 0.6
- 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()