分页

使用的Limit分页：

--语法：SELECT * FROM USER LIMIT startIndex,pageSize
SELECT * FROM USER LIMIT 0,2; --每页显示2条数据，从0开始查

使用Mybatis分页：

1、接口

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

2、UserMapper.xml

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

3、测试

package com.sw.test;

import com.sw.dao.UserMapper;
import com.sw.pojo.User;
import com.sw.utils.MybatisUtils;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;

import java.util.HashMap;
import java.util.List;
import java.util.Map;


/**
 * @Author suaxi
 * @Date 2020/12/11 17:08
 */
public class UserDaoTest {

    @Test
    public void getUserByLimit(){
        SqlSession sqlSession = MybatisUtils.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.getUserByLimit(map);
        for (User user : userlist) {
            System.out.println(user);
        }
        sqlSession.close();
    }
}

RowBounds分页：

不再使用sql实现分页

1、接口

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

2、UserMapper.xml

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

3、测试

package com.sw.test;

import com.sw.dao.UserMapper;
import com.sw.pojo.User;
import com.sw.utils.MybatisUtils;
import org.apache.ibatis.session.RowBounds;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;

import java.util.HashMap;
import java.util.List;
import java.util.Map;


/**
 * @Author suaxi
 * @Date 2020/12/11 17:08
 */
public class UserDaoTest {

    @Test
    public void getUserByRowBounds(){
        SqlSession sqlSession = MybatisUtils.getSqlSession();
        //RowBounds
        RowBounds rowBounds = new RowBounds(0, 2);
        List<User> userList = sqlSession.selectList("com.sw.dao.UserMapper.getUserByRowBounds", null, rowBounds);
        for (User user : userList) {
            System.out.println(user);
        }
        sqlSession.close();
    }
}

PageHelper

链接：https://pagehelper.github.io/