SpringBoot整合Mybatis完成增删改查功能_springboot+mybatisplus项目的增删改查实体类的id可以是int吗-优快云博客

1.我用的开发工具是Spring-tool-Suite。这个工具适合创建Spting类型的项目。（这篇文章开头有使用介绍：http://blog.youkuaiyun.com/baidu_36216018/article/details/79461016;使用IDEA工具也行，）

2.创建一个项目：

① new--->Spring Stater project

②

③：搜索需要的依赖包

④：我们发现上一步选择的依赖，在pom.xml文件中已经自动添加到我们的文件中了。

2. 开始编写代码和一些配置

先看一下我的项目的最后目录结构：

①：自己创建一个数据表字段为id ， name， password ，number 四个字段 id为int类型，其他的都为String类型。

在src/main/java目录下添加controller层，entity层，mapper层，service层

entity层的实体类User：


   
   
     
     
      
      
     
     
     
     
      
      
       
       package com.example.demo.entity;
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       public 
       
       class User {
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       private 
       
       int id;
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       private String name;
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       private String password;
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       private String number;
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       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 getPassword() {
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       return password;
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       	}
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       public void setPassword(String password) {
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       this.password = password;
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       	}
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       public String getNumber() {
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       return number;
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       	}
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       public void setNumber(String number) {
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       this.number = number;
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       	}
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       @Override
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       public String toString() {
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       return 
       
       "User [id=" + id + 
       
       ", name=" + name + 
       
       ", password=" + password + 
       
       ", number=" + number + 
       
       "]";
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       	}
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       }

mapper层的UserMapper类：


   
   
     
     
      
      
     
     
     
     
      
      
       
       package com.example.demo.mapper;
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       import java.util.List;
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       import org.apache.ibatis.annotations.Mapper;
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       import com.example.demo.entity.User;
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       @Mapper
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       public 
       
       interface UserMapper {
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       List<User> findUserByName(String name);
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       public List<User> ListUser();
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       public int insertUser(User user);
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       public int delete(int id);
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       public int Update(User user);
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       }

service层的实现类Userservice：


   
   
     
     
      
      
     
     
     
     
      
      
       
       package com.example.demo.service;
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       import java.util.List;
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       import org.springframework.beans.factory.annotation.Autowired;
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       import org.springframework.stereotype.Service;
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       import com.example.demo.entity.User;
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       import com.example.demo.mapper.UserMapper;
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       @Service
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       public 
       
       class UserService {
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       @Autowired
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       private UserMapper userMapper;
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       public List<User> findByName(String name) {
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       return userMapper.findUserByName(name);
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       	}
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       public User insertUser(User user) {
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		userMapper.insertUser(user);
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       return user;
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       	}
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       public List<User> ListUser(){
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       return	userMapper.ListUser();
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       	}
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       public int Update(User user){
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       return userMapper.Update(user);
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       	}
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       public int delete(int id){
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       return userMapper.delete(id);
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       	}
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       }

controller层的访问类CRUD:


   
   
     
     
      
      
     
     
     
     
      
      
       
       package com.example.demo.controller;
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       import java.util.List;
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       import org.springframework.beans.factory.annotation.Autowired;
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       import org.springframework.web.bind.annotation.RequestMapping;
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       import org.springframework.web.bind.annotation.RequestMethod;
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       import org.springframework.web.bind.annotation.ResponseBody;
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       import org.springframework.web.bind.annotation.RestController;
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       import com.example.demo.entity.User;
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       import com.example.demo.service.UserService;
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       @RestController
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       @RequestMapping(value = 
       
       "/CRUD", method = { RequestMethod.GET, RequestMethod.POST })
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       public 
       
       class CRUD {
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       @Autowired
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       private UserService userservice;
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       @RequestMapping(value = 
       
       "/delete", method = RequestMethod.GET)
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       public String delete(int id) {
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       int result = userservice.delete(id);
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       if (result >= 
       
       1) {
      
      
     
     

     
     
      
      
     
     
     
     
      
      			
       
       return 
       
       "删除成功";
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		} 
       
       else {
      
      
     
     

     
     
      
      
     
     
     
     
      
      			
       
       return 
       
       "删除失败";
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		}
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       	}
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       @RequestMapping(value = 
       
       "/update", method = RequestMethod.POST)
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       public String update(User user) {
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       int result = userservice.Update(user);
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       if (result >= 
       
       1) {
      
      
     
     

     
     
      
      
     
     
     
     
      
      			
       
       return 
       
       "修改成功";
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		} 
       
       else {
      
      
     
     

     
     
      
      
     
     
     
     
      
      			
       
       return 
       
       "修改失败";
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		}
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       	}
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       @RequestMapping(value = 
       
       "/insert", method = RequestMethod.POST)
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       public User insert(User user) {
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       return userservice.insertUser(user);
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		}
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       @RequestMapping(
       
       "/ListUser")
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       @ResponseBody
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       public List<User> ListUser(){
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       return userservice.ListUser();
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       	}
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       @RequestMapping(
       
       "/ListUserByname")
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       @ResponseBody
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       public List<User> ListUserByname(String name){
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       return userservice.findByName(name);
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       	}
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       }

接着：

在src/main/resources下写UserMapper的映射文件xml.

UserMapper.xml


   
   
     
     
      
      
     
     
     
     
      
      
       
       <?xml version = "1.0" encoding = "UTF-8"?>
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       <!DOCTYPE mapper PUBLIC
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
               "-//mybatis.org//DTD com.example.Mapper 3.0//EN"
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
               "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       <mapper namespace="com.example.demo.mapper.UserMapper">
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       <resultMap id="result" type="com.example.demo.entity.User">
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       <result property="name" column="name" />
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       <result property="password" column="password" />
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       <result property="number" column="number"/>
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       </resultMap>
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       <select id="ListUser" resultMap="result">
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		SELECT * FROM user
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       </select>
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       <select id="findUserByName" resultMap="result">
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		SELECT * FROM user where name=#{name}
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       </select>
      
      
     
     

     
     
      
      
     
     
     
     
      
       
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       <insert id="insertUser" parameterType="com.example.demo.entity.User"
      
      
     
     

     
     
      
      
     
     
     
     
      
      		
       
       keyProperty=
       
       "id" 
       
       useGeneratedKeys=
       
       "true">
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		INSERT INTO user
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		(
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		id,name,password,number
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		)
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		VALUES (
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		#{id},
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		#{name, jdbcType=VARCHAR},
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		#{password, jdbcType=VARCHAR},
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		#{number}
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		)
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       </insert>
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       <delete id="delete" parameterType="int">
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       		delete from user where id=#{id}
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       </delete>
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       <update id="Update" parameterType="com.example.demo.entity.User">
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       	update user set user.name=#{name},user.password=#{password},user.number=#{number} where user.id=#{id}
      
      
     
     

     
     
      
      
     
     
     
     
      
      	
       
       </update>
      
      
     
     

     
     
      
      
     
     
     
     
      
      
       
       </mapper>

最后配置application.properties配置文件：

spring.datasource.url = jdbc:mysql://localhost:3306/test
spring.datasource.username = root
spring.datasource.password = 11111111
spring.datasource.driverClassName = com.mysql.jdbc.Driver
spring.datasource.max-active=20
spring.datasource.max-idle=8
spring.datasource.min-idle=8
spring.datasource.initial-size=10
mybatis.mapper-locations= classpath:mapper/*.xml