MyBatis-Plus分页时排序的实现方法

目录

• 简介
• 建库建表
• 依赖
• 配置
• Entity
• Service
• Controller
• 测试
• 1.不指定顺序
• 2.后端OrderItem排序（create_time倒序）
• 3.后端Wrapper排序（create_time倒序，id升序）
• 4.前端指定排序（create_time倒序）

简介

说明

本文用示例介绍MyBtisPlus分页时排序的方法。

分页时排序的方法

• 后端OrderItems排序
• 后端Wrapper排序
• 前端指定排序

排序涉及到的类

排序涉及到Page类的List<OrderItem> orders;成员，OrderItem定义如下：

public class OrderItem implements Serializable {
    private static final long serialVersionUID = 1L;

    //需要进行排序的字段
    private String column;
    // 是否正序排列，默认 true
    private boolean asc = true;
    ...
}

建库建表

DROP DATABASE IF EXISTS mp;
CREATE DATABASE mp DEFAULT CHARACTER SET utf8;
USE mp;

DROP TABLE IF EXISTS `t_user`;
SET NAMES utf8mb4;
CREATE TABLE `t_user`
(
    `id`           BIGINT(0) NOT NULL AUTO_INCREMENT,
    `user_name`    VARCHAR(64) NOT NULL COMMENT '用户名（不能重复）',
    `nick_name`    VARCHAR(64) NULL COMMENT '昵称（可以重复）',
    `email`        VARCHAR(64) COMMENT '邮箱',
    `create_time`  DATETIME(0) NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
    `update_time`  DATETIME(0) NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '修改时间',
    `deleted_flag` BIGINT(0) NOT NULL DEFAULT 0 COMMENT '0：未删除 其他：已删除',
    PRIMARY KEY (`id`) USING BTREE,
    UNIQUE KEY `index_user_name_deleted_flag` (`user_name`, `deleted_flag`),
    KEY `index_create_time`(`create_time`)
) ENGINE = InnoDB COMMENT = '用户';
INSERT INTO `t_user` VALUES (1, 'knife', '刀刃', 'abc@qq.com', '2021-01-23 09:33:36', '2021-01-23 09:33:36', 0);
INSERT INTO `t_user` VALUES (2, 'sky', '天蓝', '123@qq.com', '2021-01-24 18:12:21', '2021-01-24 18:12:21', 0);

执行后的结果：

依赖

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.12.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>MyBatis-Plus_Simple</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>MyBatis-Plus_Simple</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.1</version>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <groupId>com.github.xiaoymin</groupId>
            <artifactId>knife4j-spring-boot-starter</artifactId>
            <version>3.0.3</version>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

配置

application.yml

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://127.0.0.1:3306/mp?characterEncoding=UTF-8&serverTimezone=Asia/Shanghai
    username: root
    password: 222333

#mybatis-plus配置控制台打印完整带参数SQL语句
mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

分页插件的配置（必须）

package com.example.demo.config;
import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
@Configuration
public class MyBatisPlusConfig {
    /**
     * 分页插件
     */
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return interceptor;
    }
}

代码

Entity

package com.example.demo.user.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableLogic;
import com.baomidou.mybatisplus.annotation.TableName;
import com.baomidou.mybatisplus.extension.activerecord.Model;
import lombok.Data;
import java.time.LocalDateTime;
@Data
@TableName(value = "t_user")
public class User {
    @TableId(value = "id", type = IdType.AUTO)
    private Long id;
    /**
     * 用户名（不能重复）
     */
    private String userName;
     * 昵称（可以重复）
    private String nickName;
     * 邮箱
    private String email;
     * 创建时间
    private LocalDateTime createTime;
     * 修改时间
    private LocalDateTime updateTime;
     * 0：未删除 其他：已删除
    @TableLogic(delval = "id")
    private Long deletedFlag;
}

Service

接口

package com.example.demo.user.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.example.demo.user.entity.User;
public interface UserService extends IService<User> {
}

实现

package com.example.demo.user.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.example.demo.user.entity.User;
import com.example.demo.user.mapper.UserMapper;
import com.example.demo.user.service.UserService;
import org.springframework.stereotype.Service;
@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {
}

Controller

package com.example.demo.user.controller;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.core.metadata.OrderItem;
import com.baomidou.mybatisplus.core.toolkit.Wrappers;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.example.demo.user.entity.User;
import com.example.demo.user.service.UserService;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;
@Api(tags = "排序")
@RestController
@RequestMapping("sort")
public class SortController {
    @Autowired
    private UserService userService;
    @ApiOperation("默认顺序")
    @GetMapping("defaultOrder")
    public IPage<User> defaultOrder(Page<User> page) {
        return userService.page(page);
    }
    @ApiOperation("通过orderItems")
    @GetMapping("orderItems")
    public IPage<User> orderItems(Page<User> page) {
        page.addOrder(OrderItem.desc("create_time"));
        // 可以指定多列。比如下边这个：按create_time排序，若create_time相同，则按id排序
        // page.addOrder(OrderItem.desc("create_time"), OrderItem.asc("id"));
    @ApiOperation("通过wrapper")
    @GetMapping("wrapper")
    public IPage<User> wrapper(Page<User> page) {
        LambdaQueryWrapper<User> queryWrapper = Wrappers.<User>lambdaQuery();
        // 按create_time排序，若create_time相同，则按id排序
        queryWrapper.orderByDesc(User::getCreateTime);
        queryWrapper.orderByAsc(User::getId);
        return userService.page(page, queryWrapper);
    @ApiOperation("前端指定顺序")
    @GetMapping("byFrontEnd")
    public IPage<User> byFrontEnd(Page<User> page) {
}

测试

访问Knife4j页面：http://localhost:8080/doc.html

1.不指定顺序

本处前端不传任何参数进行的测试。

2.后端OrderItem排序（create_time倒序）

本处前端不传任何参数进行的测试。

3.后端Wrapper排序（create_time倒序，id升序）

本处前端不传任何参数进行的测试。

4.前端指定排序（create_time倒序）

前端指定orders[0].asc和orders[0].column

结果：

到此这篇关于MyBatis-Plus分页时的排序的文章就介绍到这了,更多相关MyBatisPlus分页排序内容请搜索我们以前的文章或继续浏览下面的相关文章希望大家以后多多支持我们！