MyBatis-Plus学习笔记(3)：分页查询

@Configuration
public class PlusConfig {
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
        // 开启 count 的 join 优化,只针对部分 left join
        paginationInterceptor.setCountSqlParser(new JsqlParserCountOptimize(true));
        return paginationInterceptor;
    }
}

	@Test
    public void testSelectPage(){
        //分页对象，构造函数传入当前页数和每页条数
        Page selectPage = new Page<User>(1, 10);
        //是否查询总条数，默认为true，也可以通过构造函数传入
        //selectPage.setSearchCount(false);

        //封装查询条件
        Wrapper wrapper = new QueryWrapper<User>().gt("id", 0).orderByDesc("id");

        //调用通用Mapper
        Page<User> resultPage = userMapper.selectPage(selectPage, wrapper);

        System.out.println("总条数：" + resultPage.getTotal());
        System.out.println("列表：" + resultPage.getRecords());

        //true，返回的对象和查询时传入的对象是同一个对象
        System.out.println(selectPage.equals(resultPage));
    }

package com.cf.plusdm.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.cf.plusdm.entity.User;

public interface UserMapper extends BaseMapper<User> {
    IPage<User> getUserList(Page<User> page);
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.cf.plusdm.mapper.UserMapper">

    <!-- 通用查询映射结果 -->
    <resultMap id="BaseResultMap" type="com.cf.plusdm.entity.User">
        <id column="id" property="id" />
        <result column="real_name" property="realName" />
        <result column="email" property="email" />
        <result column="phone" property="phone" />
    </resultMap>

    <!-- 通用查询结果列 -->
    <sql id="Base_Column_List">
        id, real_name, email, phone
    </sql>

    <select id="getUserList" resultMap="BaseResultMap">
        SELECT
        <include refid="Base_Column_List"></include>
        FROM tb_user
    </select>

</mapper>

	@Test
    public void testSelectPageXml(){
        Page resultPage = new Page<User>(1, 10);
        userMapper.getUserList(resultPage);

        System.out.println("总条数：" + resultPage.getTotal());
        System.out.println("列表：" + resultPage.getRecords());
    }