1、查询分页
- 1、使用limit SQL语句
接口中创建一个方法:(参数用map)
List<User>selectUserLimit(Map<String,Integer> map);//分页查询
xmi文件中实现接口中的方法
<selectid="selectUserLimit"resultMap="userMap1"parameterType="map">
select * from user limit #{startIndex},#{pagenum}</select><resultMapid="userMap1"type="com.liu.pojo.User"><idcolumn="pwd"property="password"></id></resultMap>
- 2、RowBounds
List<User>selectUserRowBounds();//分页查询
<selectid="selectUserRowBounds"resultType="user">
select * from user</select>
@TestpublicvoidselectUserRowBounds(){
SqlSession sqlSession= MybatisUtils.getSqlSession();
RowBounds rowBounds=newRowBounds(0,3);
List<User> userList= sqlSession.selectList("com.liu.mapper.UserMapper.selectUserRowBounds", null, rowBounds);for(User user: userList){
System.out.println(user);}
sqlSession.close();}
- 3、使用第三方插件
2、使用注解开发
- 不用再在xml文件中去实现接口,直接在接口中用注解实现sql语句
@Select("select *from user")
List<User>selectUser();//查询数据
- 绑定接口
<mappers><mapperclass="com.liu.mapper.UserMapper"/></mappers>
- 3、测试
@TestpublicvoidselectUser(){
SqlSession sqlSession= MybatisUtils.getSqlSession();//mybatis工具类的getSqlSession方法
UserMapper mapper= sqlSession.getMapper(UserMapper.class);
List<User> users= mapper.selectUser();for(User user: users){
System.out.println(user);}
sqlSession.close();}
注解可以简化代码,但是复杂语句建议还是在xml中实现