Springboot整合mybatis进行增删改查

本篇主要是讲解如何使用Springboot+mybatis对mysql数据库进行增删改查操作，下图为本次项目的目录结构：

一、首先，创建maven项目，并添加依赖。下方为pom.xml文件内容。

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.course.code</groupId>
    <artifactId>Test190313</artifactId>
    <version>1.0-SNAPSHOT</version>


    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.0.RELEASE</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.16.14</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.21</version>
        </dependency>

        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>RELEASE</version>
            <scope>compile</scope>
        </dependency>
    </dependencies>

</project>

二、本次项目需要涉及到mysql数据库操作，因此先新建数据库、新建表，并添加表字段，如下图course数据库中新建了user表

下图为user表字段：

三、编写springboot启动类

package com.user;

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

@SpringBootApplication
@MapperScan(value = "com.user.dao")
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class,args);
    }
}

四、在com.user.entity表下新建User实体类

package com.user.entity;

import lombok.Data;

@Data
public class User {

    private int id;
    private String userName;
    private String password;
    private String age;
    private String sex;
    private String permission;
    private String isDelete;
}

 该实体类中使用了lombok工具，在项目中使用Lombok可以减少很多重复代码的书写，减少代码冗余。比如说getter/setter/toString等方法的编写。

五、编写UserMapper接口

package com.user.dao;

import com.user.entity.User;

public interface UserMapper {

    public User select(int id);

    public void addUser(User user);

    public void updateUser(User user);

    public void deleteUser(int id);
}
六、编写UserController类

package com.user.controller;

import com.user.dao.UserMapper;
import com.user.entity.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class UserController {

    @Autowired
    UserMapper userMapper;

    @RequestMapping(value = "/select",method = RequestMethod.GET)
    public User selectById(int id){
        User user;

        user = userMapper.select(id);
        return user;
    }

    @RequestMapping(value = "/addUserInfo",method = RequestMethod.POST)
    public String add(@RequestBody  User user) {

        userMapper.addUser(user);
        return "新增成功";
    }

    @RequestMapping(value = "/update",method = RequestMethod.POST)
    public String update(@RequestBody User user){

        userMapper.updateUser(user);
        return "修改成功";
    }

    @RequestMapping(value = "/delete",method = RequestMethod.POST)
    public String delete(int id){

        userMapper.deleteUser(id);
        return "删除成功";
    }
}
七、编写application.properties文件

server.port=9797

spring.datasource.url=jdbc:mysql://localhost:3306/course
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
mybatis.mapper-locations= classpath:mapper/*.xml

八、编写UserMapper.xml文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.user.dao.UserMapper">
    <select id="select" resultType="com.user.entity.User">
        select * from user where id = #{id}
    </select>
    
    <insert id="addUser" parameterType="com.user.entity.User">
         insert into user(id,userName,password,age,sex,permission,isDelete)
         values(#{id},#{userName},#{password},#{age},#{sex},#{permission},#{isDelete})
    </insert>

    <update id="updateUser">
        update user set userName=#{userName},age=#{age} where id=#{id}
    </update>

    <delete id="deleteUser" parameterType="int">
        delete from user where id =#{id}
    </delete>
</mapper>
至此，Springboot+mybatis整合完成。