MyBatis 插入时返回刚插入记录的主键值

MyBatis 插入时返回刚插入记录的主键值

一、要求：

1、数据库表中的主键是自增长的，如：id；

2、获取刚刚插入的记录的id值；

二、源代码：

1、User.java

 package cn.com.zfc.model;

 public class User {

     private Integer id;
     private String name;
     private String password;

     public Integer getId() {
         return id;
     }

     public void setId(Integer id) {
         this.id = id;
     }

     public String getName() {
         return name;
     }

     public void setName(String name) {
         this.name = name;
     }

     public String getPassword() {
         return password;
     }

     public void setPassword(String password) {
         this.password = password;
     }

     @Override
     public String toString() {
         return "User [id=" + id + ", name=" + name + ", password=" + password + "]";
     }

 }

2、UserMapper.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 <mapper namespace="cn.com.zfc.model.UserMapper">

     <!-- 插入一条记录开始，返回主键插入记录的id -->
     <insert id="insert" parameterType="cn.com.zfc.model.User">
         insert into user
         (name,password)
         values
         (#{name},#{password})
         <!--
             selectKey中order属性的值是不同的，BEFORE先选择主键，设置keyProperty的值然后执行插入语句。
              AFTER是先执行插入语句，然后执行selectKey。
          -->
         <selectKey keyColumn="id" keyProperty="id" order="AFTER"
             resultType="Integer">
             SELECT LAST_INSERT_ID() AS id
         </selectKey>
     </insert>
     <!-- 插入一条记录结束 -->
 </mapper>

3、mybatis-config.xml

 <?xml version="1.0" encoding="UTF-8" ?>
 <!DOCTYPE configuration
 PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
 "http://mybatis.org/dtd/mybatis-3-config.dtd">
 <configuration>
     <environments default="development">
         <environment id="development">
             <transactionManager type="JDBC" />
             <!-- 配置数据源 -->
             <dataSource type="POOLED">
                 <property name="driver" value="com.mysql.jdbc.Driver" />
                 <property name="url" value="jdbc:mysql://localhost:3306/mybatis_07" />
                 <property name="username" value="root" />
                 <property name="password" value="root" />
             </dataSource>
         </environment>
     </environments>
     <!-- 注册映射文件 -->
     <mappers>
         <!-- 注册映射文件，xml：resource -->
         <mapper resource="cn/com/zfc/model/UserMapper.xml" />
     </mappers>
 </configuration>

4、MyBatisUtil.java

 package cn.com.zfc.util;

 import java.io.IOException;
 import java.io.InputStream;

 import org.apache.ibatis.io.Resources;
 import org.apache.ibatis.session.SqlSessionFactory;
 import org.apache.ibatis.session.SqlSessionFactoryBuilder;

 public class MyBatisUtil {

     private static SqlSessionFactoryBuilder sqlSessionFactoryBuilder = null;
     private static SqlSessionFactory sessionFactory = null;
     private static InputStream inputStream = null;

     static {
         try {
             // 加载mybatis主配置文件
             inputStream = Resources.getResourceAsStream("mybatis-config.xml");
             sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
             // 获取SqlSessionFactory对象
             sessionFactory = sqlSessionFactoryBuilder.build(inputStream);
         } catch (IOException e) {
             e.printStackTrace();
         }
     }

     /**
      * 获取SqlSessionFactory对象
      *
      * @return
      */
     public static SqlSessionFactory getSqlSessionFactory() {
         return sessionFactory;
     }
 }

5、MyBatisTest.java

 package cn.com.zfc.test;

 import org.apache.ibatis.session.SqlSession;
 import org.apache.ibatis.session.SqlSessionFactory;

 import cn.com.zfc.model.User;
 import cn.com.zfc.util.MyBatisUtil;

 /**
  * 获取刚插入数据库表中记录的自增长主键
  *
  * @title MyBatisTest
  * @describe
  * @author 张富昌
  * @date 2017年8月22日下午10:56:58
  */
 public class MyBatisTest {
     public static void main(String[] args) {

         // 1、获取SqlSessionFactory
         SqlSessionFactory sqlSessionFactory = MyBatisUtil.getSqlSessionFactory();
         // 2、获取SqlSession
         SqlSession sqlSession = sqlSessionFactory.openSession();
         String statement = "cn.com.zfc.model.UserMapper.insert";
         User user = new User();
         user.setName("张富昌2");
         user.setPassword("123456");
         // 执行添加操作之后返回的结果
         int result = sqlSession.insert(statement, user);
         // 提交
         sqlSession.commit();
         // 关闭
         sqlSession.close();
         System.out.println("result:" + result);
         // 获取刚刚添加进去的自增长主键id
         System.out.println("id:" + user.getId());
     }
 }

 三、运行效果