Mybatis-06分页

思考：为什么要分页？ 1、减少数据的处理量

7.1使用limit分页

语法：select * from mybatis.user limit startIndex,pageSize; select * from mybatis.user limit 0,2;从0-2 select * from mybatis.user limit 3;从0-3

使用mybatis实现分页 核心Sq 接口：

//分页 List<User> getUserByLimit(Map<String,Integer>map);

Mapper.Xml:

<select id="getUserByLimit" parameterType="Map" resultMap="UserMap"> select * from mybatis.user limit #{startIndex},#{pageSize} </select>

测试：

@Test public void getUserByLimit(){ SqlSession sqlSession = Utils.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(); }

7.2RowBounds分页 不再用Sql实现 接口：

//分页2 List<User> getUserByRowbounds(Map<String,Integer>map);

Mapper.Xml:

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

测试：

@Test public void getUserByRowbounds(){ SqlSession sqlSession = Utils.getSqlSession(); //Rowbounds实现 RowBounds rowBounds = new RowBounds(1, 2); //通过java代码来实现 List<User> userList = sqlSession.selectList("com.Dao.UserMapper.getUserByRowbounds",null,rowBounds); for (User user : userList) { System.out.println(user); } sqlSession.close(); }