Mybatis-Plus基础实现最基本的crud

一、准备

   1、创建数据库表

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)
);


SELECT * FROM USER

INSERT INTO USER (id, NAME, age, email) VALUES
(1, 'Jone', 18, '[email protected]'),
(2, 'Jack', 20, '[email protected]'),
(3, 'Tom', 28, '[email protected]'),
(4, 'Sandy', 21, '[email protected]'),
(5, 'Billie', 24, '[email protected]');

 二、初始化一个SpringBoot工程

        我的项目结构如下：

        

     2.1 加入相关依赖：

    
        org.springframework.boot
        spring-boot-starter-parent
        2.0.3.RELEASE
        
    
    
        
            org.springframework.boot
            spring-boot-starter
        
        
        
            org.springframework.boot
            spring-boot-starter-test
            test
        
        
        
            org.projectlombok
            lombok
            true
        
        
        
            com.baomidou
            mybatis-plus-boot-starter
            3.1.0
        
        
        
            mysql
            mysql-connector-java
            5.1.35
        
    

  2.2 yml文件配置：

server:
  port: 8888
spring:
  application:
    name: user-service
  datasource:
    url: jdbc:mysql://127.0.0.1:3306/test
    username: root
    password: 1234
    driver-class-name: com.mysql.jdbc.Driver

 2.3、创建对应实体、mapper接口

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {

    private Long id;

    private  String name;

    private  Integer age;

    private  String email;






}

 

/**
 * 用户的mapper
 */
public interface UserMapper extends BaseMapper {
}

三、创建测试用例完成crud

@SpringBootApplication
@MapperScan("com.snym.mapper")
public class ApplicationStart {


    public static void main(String[] args) {
        SpringApplication.run(ApplicationStart.class,args);
    }
}

package com.snym.usertest;

import com.snym.entity.User;
import com.snym.mapper.UserMapper;
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.ArrayList;
import java.util.List;

/**
 *
 * @author acer
 * @create 2019/3/25
 * @since 1.0.0
 */
@RunWith(SpringRunner.class)
@SpringBootTest
public class SampleTest {

    @Autowired
    private UserMapper userMapper;


    @Test
    public void testSelect(){
        System.out.println("select all");
        List users = userMapper.selectList( null );
        User user = userMapper.selectById( 1 );
        System.out.println(user);

        users.forEach(System.out::println);
    }

    @Test
    public  void testSave(){
        System.out.println("add one userInfo");
        //新增一条user信息
        int result = userMapper.insert( new User( 7l, "lisi", 22, "kajdakjdka.com" ) );

        System.out.println(result);


    }

    @Test
    public  void testUpdate(){

        System.out.println("update one userInfo");

        User user = new User();
        user.setAge(26);

        user.setId(6l);

        int i = userMapper.updateById( user );
        System.out.println(i);

    }

    @Test
    public  void testDelete(){
        System.out.println("delete one userInfo");
        int i = userMapper.deleteById( 6 );
        System.out.println(i);

    }

    @Test
    public  void testSelectBatchIds(){
        System.out.println("查询（根据ID 批量查询）");

        List ids=new ArrayList<>();
        ids.add(1);
        ids.add(2);

        List users = userMapper.selectBatchIds( ids );

        users.forEach( System.out::println);


    }











}