springboot+mybatis 实现对数据库的增删改查_springboot连接数据库增删改查

一、插入数据库

0、在pom.xml文件里面导入mysql驱动

 <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

 在pom.xml里面导入mybatis依赖

      <!--导入mybatis依赖-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>
        <!--导入mybatis依赖-->

1、连接数据库的配置

在application.properties里面

spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.cj.jdbc
spring.datasource.url=jdbc:mysql://localhost:3306/idea?serverTimezone=UTC&characterEncoding=utf-8

2、创建表

3、创建bean类

package mybatiscrud.model;
 
public class user {
    private int id;
    private String username;
    private String password;
    private String tell;
 
    public void setId(int id) {
        this.id = id;
    }
 
    public void setPassword(String password) {
        this.password = password;
    }
 
    public void setUsername(String username) {
        this.username = username;
    }
 
    public void setTell(String tell) {
        this.tell = tell;
    }
 
    public int getId() {
        return id;
    }
 
    public String getPassword() {
        return password;
    }
 
    public String getUsername() {
        return username;
    }
 
    public String getTell() {
        return tell;
    }
}

4、dao层

package com.example.mybatiscrud.dao;
import com.example.mybatiscrud.model.user;
import org.apache.ibatis.annotations.Mapper;
import java.util.List;
@Mapper
public interface UserDao {
    //插入
     int insert(user u);
    //删除
    int delete(int id);
    //修改
    int update(user u);
    //查询all
    List<user> query();
    //条件查询
    List<user> queryby(String u);
}

5、服务层 

package com.example.mybatiscrud.service;
import com.example.mybatiscrud.dao.UserDao;
import com.example.mybatiscrud.model.user;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class UserService {
    @Autowired
    private UserDao ud;
    public int insert(user u){
        return ud.insert(u);
    };
    //删除
    public int delete(int id){
        return ud.delete(id);
    };
    //修改
   public int update(user u){
       return ud.update(u);
   };
    //查询all
    public List<user> query(){
        return ud.query();
    };
    //条件查询
    public user queryby(int c){
        System.out.println("service:"+c);
        return ud.queryby(c);
    };
}

6、控制层

package com.example.mybatiscrud.control;
import com.