学习：MyBatis Plus （1）

http://【尚硅谷Java项目【尚庭公寓】从0开始Java项目实战】https://www.bilibili.com/video/BV1At421K7gP?p=59&vd_source=435647b5da1386aa0413f7715c71b024

新建库

新建表

插入数据

Mybatis Plus与SpringBoot的集成

创建项目

再引入mybatis plus

复制代码

<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.5.3.2</version>
</dependency>

设置application.yml

复制代码

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: root
    url: jdbc:mysql://localhost:3306/hello_mp?useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT%2B8

创建实体类，新建文件夹entity

注解说明

创建Mapper接口，新建文件夹mapper

创建UserMapper.java

创建测试，确定

运行 'testList()'(U)，打印出sql语句

创建testSelectById并运行

创建testInsert并运行

创建testUpdateById并运行

创建testDeleterById并运行

创建service接口，新建文件夹service

创建service实现类，新建文件夹Impl

创建测试类

创建testGetById并运行

创建testSaveOrUpdate并运行

创建testSaveBatch并运行

条件构造器，新建文件夹wrapper

创建testQueryWrapper方法并运行

查询name=张三的所有用户

查询邮箱域名为baomidou.com的所有用户

查询所有用户信息并按照age字段降序排序

查询前age介于 $20，30$ 的所有用户

查询age小于20或大于30的用户

查询邮箱域名为baomidou.com且年龄小于30或大于40的用户

UpdateWrapper

将name=Tom的用户的emai1改为Tom@baobidou.com

创建LambdaWrapperTest

复制代码

package org.example.mybatisplusdemo.wrapper;

import org.example.mybatisplusdemo.service.UserService;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
public class LambdaWrapperTest {
    @Autowired
    private UserService userService;

    @Test
    public void testLambdaQueryWrapper() {
    }

    @Test
    public void testLambdaUpdateWrapper() {
    }
}

查询name=Tom的所有用户

将name=Tom的用户的邮箱改为Tom@tom.com

分页插件

创建config文件夹

MPConfiguration.java

java 复制代码

package org.example.mybatisplusdemo.config;


import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class MPConfiguration {
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return interceptor;
    }
}

创建测试类PageTest

java 复制代码

package org.example.mybatisplusdemo.page;

import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import org.example.mybatisplusdemo.entity.User;
import org.example.mybatisplusdemo.mapper.UserMapper;
import org.example.mybatisplusdemo.service.UserService;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
public class PageTest {
    @Autowired
    private UserMapper userMapper;
    @Autowired
    private UserService UserService;

    @Test
    public void testPageService() {

    }

    @Test
    public void testPageMapper() {

    }

    @Test
    public void testCustomMapper() {

    }

}

service

mapper

自定义mapper

UserMapper.java

java 复制代码

package org.example.mybatisplusdemo.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import org.apache.ibatis.annotations.Mapper;
import org.example.mybatisplusdemo.entity.User;

@Mapper
public interface UserMapper extends BaseMapper<User> {
    IPage<User> selectUserPage(IPage<User> page);

}

在application.yml中添加

java 复制代码

mybatis-plus:
  configuration:
  mapper-locations: classpath*:/mapper/**/*.xml

创建mapper.UserMapper.xml

html 复制代码

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//oT0 Happer 3.o//EN"
        "http://mybatis.org/atd/mybatis-3-mapper.dtd">
<mapper namespace="org.example.mybatisplusdemo.mapper.UserMapper">
    <select id="selectuserPage" resultType="com.atguigu.hellomp.entity.User">
        select *
        from user
    </select>
</mapper>

运行测试类

MyBatisX

添加数据源

控制台位置

生成配置

下一步

选择

完成

在UserMapper.java处添加@Mapper

全部测试通过