Mybatis-Plus进行增删改查

前言:本文用于练习Mybatis-Plus的增删改查

Mybatis:

MyBatis 是支持普通 SQL 查询,存储过程和高级映射的优秀持久层框架。MyBatis 消除了几乎所有的 JDBC 代码和参数的手工设置以及结果集的检索。

1.简化JDBC的开发
2.能够更好的完成ORM(对象关系映射)

Mybatis-Plus:

mybatis-plus 是在 mybatis 上的增强，减少了 xml 的配置，几乎不用编写xml就可以做到单表的 CURD,很是方便，极大提供了开发的效率。

 

建立数据库和数据表

 

创建项目

 

目录结构

 

database连接数据库并配置maven

 

 

 

pom.xml文件

    4.0.0

    org.example
    ssr
    1.0-SNAPSHOT
    
        1.8
        UTF-8
        UTF-8
        2.4.1
    

    

        
            org.springframework.boot
            spring-boot-starter-web
        

        
            org.springframework.boot
            spring-boot-starter-test
            test
            
                
                    org.junit.vintage
                    junit-vintage-engine
                
            
        

        
        
            com.baomidou
            mybatis-plus-boot-starter
            3.4.3
        
        
            com.baomidou
            mybatis-plus-generator
            3.5.1
        


        
        
            mysql
            mysql-connector-java
        

        
        
            org.projectlombok
            lombok
        
        
            junit
            junit
        
        
            org.springframework.boot
            spring-boot-test
        
    

    
        
            
                org.springframework.boot
                spring-boot-dependencies
                ${spring-boot.version}
                pom
                import
            
        
    

    
        
            
                org.apache.maven.plugins
                maven-compiler-plugin
                3.8.1
                
                    1.8
                    1.8
                    UTF-8
                
            
            
                org.springframework.boot
                spring-boot-maven-plugin
                2.4.1
                
                    com.jt.SsrApplication
                
                
                    
                        repackage
                        
                            repackage
                        
                    
                
            
        
    

配置yml文件

 

 

启动类

package com.jt;

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

@SpringBootApplication
@MapperScan("com.jt.mapper")
public class SsrApplication {
    public static void main(String[] args) {
        SpringApplication.run(SsrApplication.class,args);
    }
}

实体类

package com.jt.pojo;

import com.baomidou.mybatisplus.annotation.TableName;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.experimental.Accessors;
import org.springframework.format.annotation.DateTimeFormat;

import java.io.Serializable;
import java.sql.Date;

@Data
@NoArgsConstructor
@AllArgsConstructor
@Accessors(chain = true)
@TableName("User")
public class User implements Serializable {
    private Integer runoobId;
    private String runoobTitle;
    private String runoobAuthor;
    @DateTimeFormat(pattern="yyyy-MM-dd")
    private Date submissionDate;
}

SysResult

package com.jt.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.experimental.Accessors;

import java.io.Serializable;

@Data
@Accessors(chain = true)
@NoArgsConstructor
@AllArgsConstructor
public class SysResult implements Serializable {
    private Integer status; //200成功  201失败
    private String  msg;    //提示信息
    private Object  data;   //服务器返回值数据

    public static SysResult fail(){

        return new SysResult(201,"业务调用失败!!",null);
    }

    public static SysResult success(){

        return new SysResult(200,"业务调用成功!!",null);
    }


    public static SysResult success(Object data){

        return new SysResult(200,"业务调用成功!!",data);
    }

    public static SysResult success(String msg,Object data){

        return new SysResult(200,msg,data);
    }
}

controller

package com.jt.controller;

import com.jt.pojo.SysResult;
import com.jt.pojo.User;
import com.jt.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping("/user")
public class UserController {
    @Autowired
    private UserService userService;

    @GetMapping("/findAll")
    public List findAll(){

        return userService.findAll();
    }

    @DeleteMapping("/deleteUserById/{id}")
    public SysResult deleteUserById(@PathVariable Integer id){
        userService.deleteUserById(id);
        return SysResult.success();
    }


    @GetMapping("/findUserById/{id}")
    public SysResult findUserById(@PathVariable Integer id){

        return SysResult.success(userService.findUserById(id));
    }

    @PostMapping("/add")
    public SysResult addUser(@RequestBody() User user){
        userService.addUser(user);
        return SysResult.success();
        //return SysResult.success(userService.addUser(user));
    }

    @PutMapping("/updateUser")
    public SysResult updateUser(@RequestBody User user){
        userService.updateUser(user);
        return SysResult.success();
        //return SysResult.success(userService.updateUser(user));
    }


    @PutMapping("/update")
    public SysResult update(@RequestBody User user){
        userService.update(user);
        return SysResult.success();
    }
}

mapper

package com.jt.mapper;

import com.jt.pojo.User;

import java.util.List;


public interface UserMapper {

    List findAll();

    void deleteUserById(Integer id);

    void updateUser(User user);

    void addUser(User user);

    User findUserById(Integer id);

    void update(User user);

}

Service

package com.jt.mapper;

import com.jt.pojo.User;

import java.util.List;


public interface UserMapper {

    List findAll();

    void deleteUserById(Integer id);

    void updateUser(User user);

    void addUser(User user);

    User findUserById(Integer id);

    void update(User user);

}

package com.jt.service;

import com.jt.mapper.UserMapper;
import com.jt.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

@Service
public class UserServiceImpl implements UserService{

    @Autowired
    private UserMapper userMapper;



    @Override
    public List findAll() {

        return userMapper.findAll();
    }

    @Override
    @Transactional
    public void deleteUserById(Integer id) {

        userMapper.deleteUserById(id);
    }

    @Override
    public User findUserById(Integer id) {
        return userMapper.findUserById(id);
    }


    @Override
    public void updateUser(User user) {

        userMapper.updateUser(user);
    }

    @Override
    public void addUser(User user) {

        userMapper.addUser(user);
    }


    @Override
    public void update(User user){

        userMapper.update(user);
    }

}

UserMapper.xml

    
        select * from runoob_tbl
    

    
        select * from runoob_tbl where runoob_id=#{runoob_id}
    

    
        delete from runoob_tbl where runoob_id=#{runoob_id}
    


    
        INSERT INTO runoob_tbl VALUES (20,'zzz','xxx','2022-05-18');
    

    
        UPDATE runoob_tbl SET runoob_id=8 WHERE runoob_id=10;
    


    
        update runoob_tbl set submission_date = "2022-10-01" where submission_date = "2022-10-20";
    

api.http