搭建MyBatis-Plus框架并进行数据库增删改查功能

目录

• 1.搭建环境

• 2.项目搭建

• 3.配置maven

• 4.项目结构

• 5.配置 MapperScan 注解

• 6.创建实体

• 7.创建接口

• 8.测试

• 8.1 updateById

• 8.2 selectById

• 8.3 deleteById

搭建MyBatis-Plus框架并进行数据库添加

MyBatis-Plus（简称 MP）是一个 MyBatis 的增强工具，在 MyBatis 的基础上只做增强不做改变，为简化开发、提高效率而生。

1.搭建环境

Jdk：jdk1.8.0_261
Idea：IntelliJ IDEA
Maven：apache-maven-3.3.6
MySQL：mysql-5.5.61

2.项目搭建

3.配置maven

4.项目结构

创建数据库

CREATE DATABASE tzy03;

USE tzy03;

CREATE TABLE user(
id INT(11) PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(50),
pass VARCHAR(50),

);

INSERT INTO user(name,passs) VALUES('Tom','1215');

SELECT * FROM user;

新建完成以后，打开pom.xml后添加以下依赖：

<dependency>
  <groupId>com.baomidou</groupId>
  <artifactId>mybatis-plus-boot-starter</artifactId>
  <version>3.4.0</version>
 </dependency>
 <dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
  <version>5.1.49</version>
 </dependency>
 <dependency>
  <groupId>org.projectlombok</groupId>
  <artifactId>lombok</artifactId>
  <version>1.18.12</version>
  <scope>provided</scope>
 </dependency>
 <dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-test</artifactId>
 </dependency>

5.配置 MapperScan 注解

扫描mapper层

package com.tzy.demo;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@MapperScan("com.tzy.demo.mapper")
@SpringBootApplication
public class DemoApplication {

public static void main(String[] args) {

SpringApplication.run(DemoApplication.class, args);
}

}

成功界面

6.创建实体

package com.tzy.demo.pojo;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;

public class user {
@TableId(value = "id")
public int id;
@TableField(value = "name")
public String name;
@TableField(value = "pass")
public String pass;
@Override
public String toString() {
 return "user{" +
   "id=" + id +
   ", name='" + name + '\'' +
   ", pass='" + pass + '\'' +
   '}';
}
public user(){}
public int getId() {
 return id;
}

public void setId(int id) {
 this.id = id;
}

public String getName() {
 return name;
}

public void setName(String name) {
 this.name = name;
}

public String getPass() {
 return pass;
}

public void setPass(String pass) {
 this.pass = pass;
}

}

7.创建接口

package com.tzy.demo.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.tzy.demo.pojo.user;

import org.springframework.stereotype.Repository;

@Repository
public interface Userdao extends BaseMapper<user> {
}

8.测试

在test文件里自动生成DemoApplicationTests类里往数据库中添加数据进行测试。

package com.tzy.demo;

import com.tzy.demo.mapper.Userdao;
import com.tzy.demo.pojo.user;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class DemoApplicationTests {

@Autowired
private Userdao userdao;

@Test
 void insert(){
  user user1=new user();
  user1.setName("田哲沅");
  user1.setPass("1218");

int result=userdao.insert(user1);
  System.out.println("result:"+result);
  System.out.println(user1);//id会自动回填到user对象中
 }

}

成功界面

8.1 updateById

需求信息：将id为1的员工的姓名更改为"tzy"

@Test
void testUpdateById() {
 user user2=userdao.selectById(1);
 user2.setName("tzy");
 int result = userdao.updateById(user2);
 System.out.println(result);
}
}

8.2 selectById

查询id为1的员工信息

@Test
void selectById() {
 user user2=userdao.selectById(1);
 System.out.println(user2);
}
}

8.3 deleteById

删除id为1的员工信息

@Test
void testDeleteById() {
 int result = userdao.deleteById(1);
 System.out.println(result);
}

来源：https://blog.csdn.net/it1880456/article/details/114680208