【MyBatis】分页

思考：为什么要分页？

减少数据的处理量

1.使用Limit分页【核心是SQL】

SQL语法：

语法：SELECT * from user limit startIndex,pageSize; SELECT * from user limit 3; #[0,n] 接口 //分页 List<User> getUserByLimit(Map<String,Integer> map); Mapper.xml <!--//分页--> <select id="getUserByLimit" parameterType="map" resultMap="UserMap"> select * from mybatis.user limit #{startIndex},#{pageSize} </select> 测试 @Test public void getUserByLimit(){ SqlSession sqlSession = MybatisUtils.getSqlSession(); UserMapper mapper = sqlSession.getMapper(UserMapper.class); HashMap<String, Integer> map = new HashMap<String, Integer>(); map.put("startIndex",1); map.put("pageSize",2); List<User> userList = mapper.getUserByLimit(map); for (User user : userList) { System.out.println(user); } sqlSession.close(); }

RowBounds分页

接口 //分页2 List<User> getUserByRowBounds(); mapper.xml <!--分页2--> <select id="getUserByRowBounds" resultMap="UserMap"> select * from mybatis.user </select> 测试 @Test public void getUserByRowBounds(){ SqlSession sqlSession = MybatisUtils.getSqlSession(); //RowBounds实现 RowBounds rowBounds = new RowBounds(1, 2); //通过Java代码层面实现分页 List<User> userList = sqlSession.selectList("com.kuang.dao.UserMapper.getUserByRowBounds",null,rowBounds); for (User user : userList) { System.out.println(user); } sqlSession.close(); }