（四）MyBaits使用Map實現插入和查詢

當資料庫中的表欄位過多的時候，考慮使用Map的方式進行插入。

• 資料庫

• 環境

  使用了MyBatisUtils類封裝MyBatis功能，MyBatisUtils類在筆記（二）中

• 實現

  • insert

    Mybatis-config.xml檔案不變

    UserMapper.xml增加以下程式碼

    <insert id="insert2" parameterType="map">
        insert into mybatis.user values(#{idd},#{namee},#{pwdd})
    </insert>
    

    測試程式碼

    @Test
    public void test(){
        //獲取session物件
        SqlSession sqlSession = MybatisUtils.getSqlSession();
    
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
    
        Map<String,Object> map = new HashMap<String,Object>();
    
        map.put("idd",10);
    
        map.put("namee","zhang");
    
        map.put("pwdd","28373");
    
        int res = userMapper.insert2(map);
    
        if(res>0)
            System.out.println("succeed");
    
        sqlSession.commit();
    
        sqlSession.close();
    }
    

    測試結果，插入成功！

  • Select

    • Mybatis-config.xml檔案不變

    • UserMapper.xml增加以下程式碼

        <select id="getUserById2" parameterType="map" resultType="top.zhang.pojo.User">
                select * from user where id=#{userid} and name=#{username}
            </select>
    

    • 測試程式碼

       @Test
          public void test(){
              //獲取session物件
              SqlSession sqlSession = MybatisUtils.getSqlSession();
      
              UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
      
              Map<String,Object> map = new HashMap<String,Object>();
      
              map.put("userid",10);
      
              map.put("username","zhang");
      
      
              User user = userMapper.getUserById2(map);
      
              System.out.println(user.toString());
      
              sqlSession.commit();
      
              sqlSession.close();
          }
      

    • 查詢成功