关于mybatis:Mybatis分页查询

思考：为什么要分页?
缩小数据的处理量
1、应用Limit分页
语法:

select * from user limit startIndex,pageSize;select * from user limit 3;#[0,n]

应用Mybatis实现分页，外围SQL
接口

  /**  * 分页查问  * @return  */  List<User> getUserByLimt(Map<String,Integer> map);

Mapper.xml
<!--分页实现查问 -->
<select id="getUserByLimt" parameterType="map" resultMap="UserMap">
select * from mybatis.user limit #{startIndex},#{pageSize}
</select>

    //测试    public void getUserByLimt(){        SqlSession sqlsession = MybatisUtil.getSqlsession();        UserMapper mapper = sqlsession.getMapper(UserMapper.class);        HashMap<String, Integer> map = new HashMap<String, Integer>();        map.put("startIndex",0);        map.put("pageSize",3);        List<User> userByLimt = mapper.getUserByLimt(map);        for (User user : userByLimt) {            System.out.println(user);        }    }

2、RowBounds分页
不在应用SQL实现分页

接口

 /** * * @return */ List<User> getUserByRowBounds();

Mapper.xml

<!--分页实现查问 -->

<select id="getUserByRowBounds" resultMap="UserMap">    select * from mybatis.user</select>

  //测试public void getUserByRowBounds(){    SqlSession sqlsession = MybatisUtil.getSqlsession();    //RowBounds实现   RowBounds rowBounds = new RowBounds(1, 2);   //通过java层面实现分页   List<User> list = sqlsession.selectList("com.aostarit.dao.UserMapper.getUserByRowBounds",null,rowBounds);   for (User user : list) {       System.out.println(user);    }   //敞开sqlSession   sqlsession.close();}