mySqlJDBC驱动 最新版

1. MySQL Connector/J _______________________________________________________ MySQL provides connectivity for client applications developed in the Java programming language via a JDBC driver, which is called MySQL Connector/J. MySQL Connector/J is a JDBC-3.0 "Type 4" driver, which means that 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 A.2, "Installing Connector/J." Although JDBC is useful by itself, we would hope that if you are not familiar with JDBC that after reading the first few sections of this manual, that you would avoid using "naked" JDBC for all but the most trivial problems and consider using one of the popular persistence frameworks such as Hibernate (http://www.hibernate.org/), Spring's JDBC templates (http://www.springframework.org/) or Ibatis SQL Maps (http://ibatis.apache.org/) to do the majority of repetitive work and heavier lifting that is sometimes required with JDBC. This section is not designed to be a complete JDBC tutorial. If you need more information about using JDBC you might be interested in the following online tutorials that are more in-depth than the information presented here: * JDBC Basics (http://java.sun.com/docs/books/tutorial/jdbc/basics/index.htm l) --- A tutorial from Sun covering beginner topics in JDBC * JDBC Short Course (http://java.sun.com/developer/onlineTraining/Database/JDBCSho rtCourse/index.html) --- A more in-depth tutorial from Sun and JGuru 1.1. Basic JDBC concepts This section provides some general JDBC background. 1.1.1. Connecting to MySQL using the DriverManager Interface When you are using JDBC outside of an application server, the DriverManager class manages the establishment of Connections. The DriverManager needs to be told which JDBC drivers it should try to make Connections with. The easiest way to do this is to use Class.forName() on the class that implements the java.sql.Driver interface. With MySQL Connector/J, the name of this class is com.mysql.jdbc.Driver. With this method, you could use an external configuration file to supply the driver class name and driver parameters to use when connecting to a database. The following section of Java code shows how you might register MySQL Connector/J from the main() method of your application: import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; // Notice, do not import com.mysql.jdbc.* // or you will have problems! public class LoadDriver { public static void main(String[] args) { try { // The newInstance() call is a work around for some // broken Java implementations Class.forName("com.mysql.jdbc.Driver").newInstance(); } catch (Exception ex) { // handle the error } } After the driver has been registered with the DriverManager, you can obtain a Connection instance that is connected to a particular database by calling DriverManager.getConnection(): Example 1. Obtaining a Connection From the DriverManager This example shows how you can obtain a Connection instance from the DriverManager. There are a few different signatures for the getConnection() method. You should see the API documentation that comes with your JDK for more specific information on how to use them. import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; ... try { Connection conn = DriverManager.getConnection("jdbc:mysql ://localhost/test?user=monty&password=greatsqldb"); // Do something with the Connection .... } catch (SQLException ex) { // handle any errors System.out.println("SQLException: " + ex.getMessage()); System.out.println("SQLState: " + ex.getSQLState()); System.out.println("VendorError: " + ex.getErrorCode()); } Once a Connection is established, it can be used to create Statement and PreparedStatement objects, as well as retrieve metadata about the database. This is explained in the following sections. 1.1.2. Using Statements to Execute SQL Statement objects allow you to execute basic SQL queries and retrieve the results through the ResultSet class which is described later. To create a Statement instance, you call the createStatement() method on the Connection object you have retrieved via one of the DriverManager.getConnection() or DataSource.getConnection() methods described earlier. Once you have a Statement instance, you can execute a SELECT query by calling the executeQuery(String) method with the SQL you want to use. To update data in the database, use the executeUpdate(String SQL) method. This method returns the number of rows affected by the update statement. If you don't know ahead of time whether the SQL statement will be a SELECT or an UPDATE/INSERT, then you can use the execute(String SQL) method. This method will return true if the SQL query was a SELECT, or false if it was an UPDATE, INSERT, or DELETE statement. If the statement was a SELECT query, you can retrieve the results by calling the getResultSet() method. If the statement was an UPDATE, INSERT, or DELETE statement, you can retrieve the affected rows count by calling getUpdateCount() on the Statement instance. Example 2. Using java.sql.Statement to Execute a SELECT Query // assume that conn is an already created JDBC connection Statement stmt = null; ResultSet rs = null; try { stmt = conn.createStatement(); rs = stmt.executeQuery("SELECT foo FROM bar"); // or alternatively, if you don't know ahead of time that // the query will be a SELECT... if (stmt.execute("SELECT foo FROM bar")) { rs = stmt.getResultSet(); } // Now do something with the ResultSet .... } finally { // it is a good idea to release // resources in a finally{} block // in reverse-order of their creation // if they are no-longer needed if (rs != null) { try { rs.close(); } catch (SQLException sqlEx) { // ignore } rs = null; } if (stmt != null) { try { stmt.close(); } catch (SQLException sqlEx) { // ignore } stmt = null; } } 1.1.3. Using CallableStatements to Execute Stored Procedures Starting with MySQL server version 5.0 when used with Connector/J 3.1.1 or newer, the java.sql.CallableStatement interface is fully implemented with the exception of the getParameterMetaData() method. MySQL's stored procedure syntax is documented in the "Stored Procedures and Functions (http://www.mysql.com/doc/en/stored-procedures.html)" 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 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); END To use the demoSp procedure with Connector/J, follow these steps: 1. Prepare the callable statement by