Mybatis(7) 分页

7.分页

    7.1 为什么要分页？

              减少数据的处理

    7.2 使用Limit分页

              语法：select *from user limit startIndex,pageSize

      

              使用Mybatis实现分页，核心Sql

1. 接口

//分页查询用户
List<User> getUsersByLimit(Map<Object,Integer> map);

1. Mapper.xml
2. 测试

<select id="getUsersByLimit" resultMap="userResultMap" parameterType="map">

    select *from mybatis.user limit #{startIndex},#{pageSize}

</select>

@Test

public void getUsersByLimit(){



    SqlSession sqlSession = MybatisUtils.getSqlSession();

    UserMapper mapper = sqlSession.getMapper(UserMapper.class);



    HashMap<Object, Integer> map = new HashMap<Object, Integer>();

    map.put("startIndex",0);

    map.put("pageSize",3);



    List<User> users = mapper.getUsersByLimit(map);

    for (User u:users) {

        System.out.println(u.toString());

    }



    sqlSession.close();

}