分页

为什么要分页?

• 减少数据的处理量

操作

1. 接口

   List<User> getUsersByLimit(Map<String, Integer> map);

1. Mapper.xml

   <select id="getUsersByLimit" parameterType="map" resultType="user">
    select * from mybatis.user limit #{startIndex}, #{pageSize}
   </select>

1. 测试

   @Test
   public void testGetUsersByLimit() {
    SqlSession sqlSession = MybatisUtil.getSqlSession();
    UserMapper mapper = sqlSession.getMapper(UserMapper.class);
    Map<String, Integer> map = new HashMap<>();
    map.put("startIndex", 0);
    map.put("pageSize", 2);
    List<User> userList = mapper.getUsersByLimit(map);
    for (User user : userList) {
        System.out.println(user);
    }
    sqlSession.close();
   }