这里将会介绍怎么去搭建一个简单增删改查的Springboot项目,认真看完我相信你一定能够学会,并且附有完整代码;
首先要进行增删改查肯定是要有供操作的数据库;
这里我是用的SQLyog来搭建的,随便用什么都可以,只要能确保给项目一个配套的数据库就行;

CREATE DATABASE springBoot;

CREATE TABLE USER( NAME VARCHAR(30), id INT(11), sex VARCHAR(10) ) DEFAULT CHARSET=utf8
打开IDEA,创建一个新项目,准备开始动手

然后选择插件


点击创建
在pom.xml里导入Lombok依赖
org.projectlombok lombok
然后搭建四层架构
controller,mapper,pojo,service

创建mapper的映射文件

在resources包下找到application.properties,将如下代码写入:
spring.datasource.username=root spring.datasource.password=admin spring.datasource.url=jdbc:mysql://localhost:3306/mybatis?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8 spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver #??mybatis mybatis.type-aliases-package=com.example.springboot.pojo mybatis.mapper-locations=classpath:mybatis/mapper/*.xml



选择我们之前建好的数据库

点击Apply和OK后,我们就可以看到我们连接了数据库

经过前面的准备工作后终于可以开始写代码了;
这里我就只介绍一个接口(查找所有用户),其他的都是差不多的流程,文章末尾附完整代码;

实体类里的属性要与数据表一一对应;

查询所有用户是要返回多个User,所以用List;

先用@Autowired注入userMapper;
然后声明方法;

同样注入
然后调用Service层
将查询的SQL语句写上

到此这个接口就算是写完了;
我建议是拿Apifox来测试,自己拿网页测试也行;
先手动添加一些数据到数据库里去;


注:一定要先让项目保持运行状态
打开浏览器,访问接口路径:
http://localhost:8080/queryUserList

package com.example.springboot.controller;
import com.example.springboot.pojo.User;
import com.example.springboot.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.List;
@RestController
public class UserController {
@Autowired
UserService userService;
@GetMapping ("/queryUserList")
public List queryUserList(){
return userService.queryUserList();
}
@GetMapping ("queryUserById")
public User queryUserById(int user_id){
return userService.queryUserById(user_id);
}
@GetMapping("/addUser")
public String addUser(User user){
return userService.addUser(user);
}
@GetMapping("/deleteUserById")
public String deleteUserById(int id){
return userService.deleteUserById(id);
}
}
package com.example.springboot.mapper;
import com.example.springboot.pojo.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;
import java.util.List;
@Mapper
@Repository
public interface UserMapper {
List queryUserList();
User queryUserById(int id);
void addUser(User user);
void deleteUserById(int id);
}
package com.example.springboot.pojo;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@NoArgsConstructor
@AllArgsConstructor
public class User {
private String name;
private int id;
private String sex;
}
package com.example.springboot.service;
import com.example.springboot.mapper.UserMapper;
import com.example.springboot.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class UserService {
@Autowired
UserMapper userMapper;
public List queryUserList(){
return userMapper.queryUserList();
}
public User queryUserById(int id){
User user= userMapper.queryUserById(id);
return user;
}
public String addUser(User user){
userMapper.addUser(user);
return "新增成功";
}
public String deleteUserById(int id){
userMapper.deleteUserById(id);
return "删除成功";
}
}
insert into springboot.user (name, id, sex) VALUES (#{name},#{id},#{sex}) delete from springboot.user where id=#{id}
spring.datasource.username=root spring.datasource.password=admin spring.datasource.url=jdbc:mysql://localhost:3306/mybatis?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8 spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver #??mybatis mybatis.type-aliases-package=com.example.springboot.pojo mybatis.mapper-locations=classpath:mybatis/mapper/*.xml server.port=8080
4.0.0 com.example springBoot 0.0.1-SNAPSHOT springBoot springBoot 1.8 UTF-8 UTF-8 2.6.13 org.mybatis.spring.boot mybatis-spring-boot-starter 2.1.1 org.projectlombok lombok org.springframework.boot spring-boot-starter-jdbc org.springframework.boot spring-boot-starter-web com.mysql mysql-connector-j runtime org.springframework.boot spring-boot-starter-test 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 ${spring-boot.version} com.example.springboot.Application true repackage repackage