mybatis-plus的使用

新建项目

pom.xml

<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
			<exclusions>
				<exclusion>
					<groupId>org.junit.vintage</groupId>
					<artifactId>junit-vintage-engine</artifactId>
				</exclusion>
			</exclusions>
		</dependency>

		<!--mybatis-plus-->
		<dependency>
			<groupId>com.baomidou</groupId>
			<artifactId>mybatis-plus-boot-starter</artifactId>
			<version>3.2.0</version>
		</dependency>

		<!--mysql-->
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
		</dependency>

		<!--lombok-->
		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
		</dependency>
	</dependencies>

数据库

entity

/**
 * Copyright (c) 2020 ucsmy.com, All rights reserved.
 */
package com.example.mybatisplusdemo.entity;

import com.baomidou.mybatisplus.annotation.TableField;
import lombok.Data;

/**
 * @Description:
 * @Author: Administrator
 * @Created Date: 2020年03月27日
 * @LastModifyDate:
 * @LastModifyBy:
 * @Version:
 */
@Data
public class User
{
    private String id;
    @TableField("USER_NAME")
    private String userName1;
    private String address;
}

mapper

/**
 * Copyright (c) 2020 ucsmy.com, All rights reserved.
 */
package com.example.mybatisplusdemo.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.example.mybatisplusdemo.entity.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

/**
 * @Description:
 * @Author: Administrator
 * @Created Date: 2020年03月27日
 * @LastModifyDate:
 * @LastModifyBy:
 * @Version:
 */
@Repository
// 这里就是通过继承BaseMapper实现基本的增删改查功能
public interface UserMapper extends BaseMapper<User>{
}

application.properties

#注意这里要加上?serverTimezone=GMT%2B8，否则会报错，springboot版本在2.2以上一定要加
spring.datasource.url=jdbc:mysql://localhost:3306/mybatis?serverTimezone=GMT%2B8
spring.datasource.username=root
spring.datasource.password=root
#下面不可以是spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
#mybatis日志
mybatis-plus.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl

测试

package com.example.mybatisplusdemo;

import com.example.mybatisplusdemo.entity.User;
import com.example.mybatisplusdemo.mapper.UserMapper;
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 MybatisPlusDemoApplicationTests {

	@Autowired
	private UserMapper mapper;

	@Test
	void findAllUsers()
	{
		List<User> userList = mapper.selectList(null);
		System.out.println(userList);
	}
}