mybatis_7分页查询

时间 2020-10-11

标签 java git github sql mybatis app 测试插件 code xml 栏目 MyBatis 繁體版

原文原文链接

思考：为何要分页？java

减小数据的处理量

7.一、使用Limit分页

语法：SELECT * from user limit startIndex,pageSize;
SELECT * from user limit 3;  #[0,n]

使用Mybatis实现分页，核心SQLgit

接口github

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

Mapper.xmlsql

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

测试mybatis

@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();
    }

7.二、RowBounds分页

再也不使用SQL实现分页，使用java代码实现分页，不推荐使用app

接口测试

//分页2
List<User> getUserByRowBounds();

mapper.xml插件

<!--分页2-->
<select id="getUserByRowBounds" resultMap="UserMap">
    select * from  mybatis.user
</select>

测试code

@Test
public void getUserByRowBounds(){
SqlSession sqlSession = MybatisUtils.getSqlSession();

//RowBounds实现
RowBounds rowBounds = new RowBounds(1, 2);

//经过Java代码层面实现分页
List<User> userList = sqlSession.selectList("com.loading.dao.UserMapper.getUserByRowBounds",null,rowBounds);

    for (User user : userList) {
    System.out.println(user);
    }

    sqlSession.close();
    }

7.三、分页插件

mybaits-pagehelperxml