From《MyBatis从入门到精通》

 

 

一、foreach实现in集合

　　1.映射文件中添加的代码：

         
                 select id,          user_name userName,          user_password userPassword,          user_email userEmail,          user_info userInfo,          head_img headImg,          create_time createTime        from sys_user        where  id in        
                          #{id}                
          

　　

　　2.接口类中添加的方法：

List
     
       selectByIdList(List
      
        idList);
      
     

 

　　3.测试代码

@Test    public void testSelectByIdList(){        SqlSession sqlSession = getSqlSession();        try{            UserMapper userMapper=sqlSession.getMapper(UserMapper.class);            List
     
       idList = new ArrayList
      
       ();            idList.add(1L);            idList.add(1001L);            List
       
         userList = userMapper.selectByIdList(idList);            Assert.assertEquals(2,userList.size());        }finally {            sqlSession.close();        }    }
       
      
     

 

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二、foreach实现批量插入

　　1.映射文件中添加的代码：

         
     
              insert into sys_user(        user_name,user_password,user_email,        user_info,head_img,create_time)        values        
      
                   (            #{user.userName},#{user.userPassword},#{user.userEmail},            #{user.userInfo},#{user.headImg,jdbcType=BLOB},            #{user.createTime,jdbcType=TIMESTAMP}            )        
          
     

　　

　　2.接口类中添加的方法：

int insertList(List
     
       userList);
     

 

　　3.测试代码：

@Test    public void testInsertList() {        SqlSession sqlSession = getSqlSession();        try{            UserMapper userMapper = sqlSession.getMapper(UserMapper.class);            List
     
       userList = new ArrayList
      
       ();            for (int i = 0; i < 2; i++) {                SysUser user = new SysUser();                user.setUserName("test"+i);                user.setUserPassword("123456");                user.setUserEmail("test@mybatis.tk");                userList.add(user);            }            int result = userMapper.insertList(userList);            Assert.assertEquals(2,result);        }finally {            sqlSession.rollback();            sqlSession.close();        }    }
      
     

 

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三、foreach实现动态UPDATE

　　1.映射文件中添加的代码：

         
     
              update sys_user        set        
      
                   ${key}=#{val}        
              where id=#{id}    
     

 

　　2.接口类中添加的方法：

int updateByMap(Map
     
       map);
     

 

　　3.测试代码：

@Test    public void testUpdateByMap(){        SqlSession sqlSession = getSqlSession();        try{            UserMapper userMapper=sqlSession.getMapper(UserMapper.class);            Map
     
       map=new HashMap
      
       ();            map.put("id",1L);            map.put("user_email","test@mybatis.tk");            map.put("user_password","1234456");            userMapper.updateByMap(map);            SysUser user = userMapper.selectById(1L);            Assert.assertEquals("test@mybatis.tk",user.getUserEmail());        }        finally {            sqlSession.rollback();            sqlSession.close();        }    }