1.MybatisPlus快速入门使用

1.创建数据库及表

1.1.创建mp库

1.2.创建user表，建表语句如下：

CREATE TABLE `user` (
  `id` bigint(20) NOT NULL COMMENT '主键',
  `name` varchar(30) DEFAULT NULL COMMENT '姓名',
  `age` int(11) DEFAULT NULL COMMENT '年龄',
  `email` varchar(50) DEFAULT NULL COMMENT '邮箱',
  `manager_id` bigint(20) DEFAULT NULL COMMENT '直属上级id',
  `create_time` datetime DEFAULT NULL COMMENT '创建时间',
  PRIMARY KEY (`id`),
  KEY `manager_fk` (`manager_id`),
  CONSTRAINT `manager_fk` FOREIGN KEY (`manager_id`) REFERENCES `user` (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

1.3.添加如下测试数据：

insert into `user` (`id`, `name`, `age`, `email`, `manager_id`, `create_time`) values('1087982257332887553','大boss','40','[email protected]',NULL,'2019-01-11 14:20:20');
insert into `user` (`id`, `name`, `age`, `email`, `manager_id`, `create_time`) values('1088248166370832385','王天风','25','[email protected]','1087982257332887553','2019-02-05 11:12:22');
insert into `user` (`id`, `name`, `age`, `email`, `manager_id`, `create_time`) values('1088250446457389058','李艺伟','28','[email protected]','1088248166370832385','2019-02-14 08:31:16');
insert into `user` (`id`, `name`, `age`, `email`, `manager_id`, `create_time`) values('1094590409767661570','张雨琪','31','[email protected]','1088248166370832385','2019-01-14 09:15:15');
insert into `user` (`id`, `name`, `age`, `email`, `manager_id`, `create_time`) values('1094592041087729666','刘红雨','32','[email protected]','1088248166370832385','2019-01-14 09:48:16');

2.创建maven项目

2.1.添加如下依赖

pom.xml文件内容：

    4.0.0
    
        org.springframework.boot
        spring-boot-starter-parent
        2.1.8.RELEASE
         
    
    com.mp
    mybatisplus
    0.0.1-SNAPSHOT
    mybatisplus
    mybatisplus

    
        1.8
    

    
        
        
            org.springframework.boot
            spring-boot-starter-web
        
        
        
            mysql
            mysql-connector-java
            runtime
        
        
        
            org.projectlombok
            lombok
            provided
        
        
        
            com.baomidou
            mybatis-plus-boot-starter
            3.2.0
        
        
        
            org.apache.commons
            commons-lang3
            3.9
        
        
        
            org.springframework.boot
            spring-boot-starter-test
            test
        
    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
        
    

2.2.在resources包下添加配置文件

application.yml配置文件内容：

server:
  port: 8088
  
spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/MP?characterEncoding=utf8&useSSL=false&serverTimezone=GMT%2B8
    username: root
    password: 123456

2.3.创建启动类

package com.mp;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

/**
 * @Description 启动类
 * @Author LL
 * @Date 2020-03-22 12:21
 */
@MapperScan("com.mp.dao")
@SpringBootApplication
public class MpApplication {
    public static void main(String[] args) {
        SpringApplication.run(MpApplication.class, args);
    }
}

2.4.创建实体类

package com.mp.entity;
import lombok.Data;
import java.time.LocalDateTime;

/**
 * @Description 实体类
 * @Author LL
 * @Date 2020-03-22 12:22
 */
@Data
public class User {

    private Long id;//主键
    private String name;//姓名
    private Integer age;//年龄
    private String email;//邮箱
    private Long managerId;//上级id
    private LocalDateTime createTime;//创建时间
    
}

2.5.创建dao接口

package com.mp.dao;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.mp.entity.User;

/**
 * @Description 数据访问层
 * @Author LL
 * @Date 2020-03-22 12:31
 */
public interface UserMapper extends BaseMapper {
}

3.编写测试类测试结果

3.1.测试类

package com.mp;

import com.mp.dao.UserMapper;
import com.mp.entity.User;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import java.util.List;

/**
 * @Description 测试类
 * @Author LL
 * @Date 2020-03-22 12:35
 */
@SpringBootTest
@RunWith(SpringRunner.class)
public class SimpleTest {

    @Autowired
    private UserMapper userMapper;

    @Test
    public void select(){
        List users = userMapper.selectList(null);
        users.forEach(System.out::println);
    }

}

3.2.测试结果