1.插入操作

CRUD实例测试

1.新建数据库

DROP TABLE IF EXISTS user;

CREATE TABLE user
(
    id BIGINT(20) NOT NULL COMMENT '主键ID',
    name VARCHAR(30) NULL DEFAULT NULL COMMENT '姓名',
    age INT(11) NULL DEFAULT NULL COMMENT '年龄',
    email VARCHAR(50) NULL DEFAULT NULL COMMENT '邮箱',
    PRIMARY KEY (id)
);


INSERT INTO user (id, name, age, email) VALUES
(1, 'Jone', 18, 'test1@baomidou.com'),
(2, 'Jack', 20, 'test2@baomidou.com'),
(3, 'Tom', 28, 'test3@baomidou.com'),
(4, 'Sandy', 21, 'test4@baomidou.com'),
(5, 'Billie', 24, 'test5@baomidou.com');

2.导入依赖

尽量不要同时导入mybatis和mybatis-plus，可能存在版本差异的问题

<!--mybatis-plus-->
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.0.5</version>
</dependency>

3.插入

pojo

package com.sw.mybatisplus.pojo;


import lombok.Data;

import java.io.Serializable;

@Data
public class User implements Serializable {

    private long id;
    private String name;
    private int age;
    private String email;


}

mapper

package com.sw.mybatisplus.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.sw.mybatisplus.pojo.User;
import org.springframework.stereotype.Repository;

/**
 * @Author suaxi
 * @Date 2021/4/4 14:46
 */
@Repository
public interface UserMapper extends BaseMapper<User> {
}

Junit单元测试

package com.sw.mybatisplus;

import com.sw.mybatisplus.mapper.UserMapper;
import com.sw.mybatisplus.pojo.User;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;

@SpringBootTest
class MybatisPlusApplicationTests {

    @Autowired
    private UserMapper userMapper;

    @Test
    void contextLoads() {
        //此处的参数是一个Wrapper（条件构造器）
        List<User> userList = userMapper.selectList(null);
        userList.forEach(System.out::println);
    }

}

控制台打印sql

# 在application.yml配置文件中添加

mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

# 或者

logging:
  level:
    com.xxx.xxx.mapper: debug

插入

@Test
void insertTest(){
    User user = new User();
    user.setName("孙笑川");
    user.setAge(33);
    user.setEmail("123321@qq.com");
    int result = userMapper.insert(user);
    System.out.println(result);
    System.out.println(user); //插入时没有手动设置，但此处的打印结果自动回填了id的值
    //User(id=0, name=孙笑川, age=33, email=123321@qq.com)

}