最近在做servlet项目的时候遇到了前后表关联得到前一个自增主键的问题,以前用ibatis的时候只需要在配置文件中配置下就可以了。搜索了下发现了解决办法。
CREATE TABLE book(
code bigint(20) unsigned NOT NULL AUTO_INCREMENT,
kind varchar(45) NOT NULL,
name varchar(45) NOT NULL,
PRIMARY KEY(code, kind)
) ENGINE = InnoDB AUTO_INCREMENT = 1 DEFAULT CHARSET = latin1
二、获取自增主键
import lavasoft.common.DBToolkit;
import java.sql.*;
/**
* JDBC获取新增记录的主键
*
* @author leizhimin 2009-12-4 13:20:15
*/
public class InsertKeyTest {
public static void main(String[] args) {
insertWithStaticSQL();
insertWithParperedSQL();
}
/**
* 预定义SQL模式,获取新增记录的主键
*/
public static void insertWithParperedSQL() {
Connection conn = null;
try {
conn = DBToolkit.getConnection();
String sql = "insert into testdb.user (name, pswd) values(?,?)";
PreparedStatement pstmt = conn.prepareStatement(sql, Statement.NO_GENERATED_KEYS);
pstmt.setString(1, "laozhang");
pstmt.setString(2, "111111");
pstmt.executeUpdate();
//检索由于执行此 Statement 对象而创建的所有自动生成的键
ResultSet rs = pstmt.getGeneratedKeys();
if (rs.next()) {
//知其仅有一 列,故获取第一列
Long id = rs.getLong(1);
System.out.println("-----预定义SQL模式-----id = " + id);
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
DBToolkit.closeConnection (conn);
}
}
/**
* 静态SQL模式,获取新增记录的主键
*/
public static void insertWithStaticSQL() {
Connection conn = null;
try {
conn = DBToolkit.getConnection();
String sql = "insert into testdb.user (name, pswd) values('ttttt','121')";
PreparedStatement pstmt = conn.prepareStatement(sql, Statement.NO_GENERATED_KEYS);
pstmt.executeUpdate();
//检索由于执行此 Statement 对象而创建的所有自动生成的键
ResultSet rs = pstmt.getGeneratedKeys();
if (rs.next()) {
//知其仅有一 列,故获取第一列
Long id = rs.getLong(1);
System.out.println("-----静态SQL模式-----id = " + id);
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
DBToolkit.closeConnection (conn);
}
}
}
执行结果:
-----静态SQL模式-----id = 8
-----预定义SQL模式-----id = 9
转自:http://www.bianceng.cn/Programming/Java/201104/25829.htm