springboot+mybatis-plus+MySQL前后端增删改查完整的demo

好的，以下是基于Spring Boot和MyBatis Plus框架搭建的MySQL前后端增删改查的完整示例代码：

1. 在pom.xml文件中添加相关依赖：

<dependencies>
    <!-- Spring Boot Web -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <!-- MyBatis Plus -->
    <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-boot-starter</artifactId>
        <version>3.4.0</version>
    </dependency>

    <!-- MySQL Connector -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.26</version>
    </dependency>

    <!-- Lombok -->
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.18.20</version>
        <scope>provided</scope>
    </dependency>
</dependencies>

2. 创建数据库表和相关实体类

CREATE DATABASE IF NOT EXISTS `test`;
USE `test`;

CREATE TABLE IF NOT EXISTS `user` (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '主键ID',
  `name` varchar(30) NOT NULL COMMENT '姓名',
  `age` int(3) NOT NULL COMMENT '年龄',
  `email` varchar(50) NOT NULL COMMENT '邮箱',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8mb4 COMMENT='用户表';

INSERT INTO `user` (`name`, `age`, `email`) VALUES ('Tom', 18, 'tom@example.com');
INSERT INTO `user` (`name`, `age`, `email`) VALUES ('Jerry', 20, 'jerry@example.com');

创建实体类User.java：

@Data
@TableName(value = "user")
public class User {
    @TableId(value = "id", type = IdType.AUTO)
    private Integer id;
    private String name;
    private Integer age;
    private String email;
}

3. 创建Mapper接口和对应的Mapper.xml文件

创建UserMapper.java：

@Mapper
public interface UserMapper extends BaseMapper<User> {
}

创建userMapper.xml：

<?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.example.demo.mapper.UserMapper">
    <resultMap id="BaseResultMap" type="com.example.demo.entity.User">
        <id column="id" property="id"/>
        <result column="name" property="name"/>
        <result column="age" property="age"/>
        <result column="email" property="email"/>
    </resultMap>

    <sql id="Base_Column_List">
        id, name, age, email
    </sql>

    <select id="selectById" resultMap="BaseResultMap">
        select
        <include refid="Base_Column_List"/>
        from user
        where id = #{id}
    </select>

    <select id="selectAll" resultMap="BaseResultMap">
        select
        <include refid="Base_Column_List"/>
        from user
    </select>

    <insert id="insert" parameterType="com.example.demo.entity.User">
        insert into user(name, age, email)
        values(#{name}, #{age}, #{email})
    </insert>

    <update id="updateById" parameterType="com.example.demo.entity.User">
        update user
        set name = #{name},
            age = #{age},
            email = #{email}
        where id = #{id}
    </update>

    <delete id="deleteById" parameterType="java.lang.Integer">
        delete from user where id = #{id}
    </delete>
</mapper>

4. 创建Service接口和实现类

创建UserService.java：

public interface UserService {

    User selectById(int id);

    List<User> selectAll();

    boolean insert(User user);

    boolean updateById(User user);

    boolean deleteById(int id);
}

创建UserServiceImpl.java：

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserMapper userMapper;

    @Override
    public User selectById(int id) {
        return userMapper.selectById(id);
    }

    @Override
    public List<User> selectAll() {
        return userMapper.selectList(null);
    }

    @Override
    public boolean insert(User user) {
        return userMapper.insert(user) > 0;
    }

    @Override
    public boolean updateById(User user) {
        return userMapper.updateById(user) > 0;
    }

    @Override
    public boolean deleteById(int id) {
        return userMapper.deleteById(id) > 0;
    }
}

5. 创建Controller类和接口

创建UserController.java：

@RestController
@RequestMapping("/user")
public class UserController {

    @Autowired
    private UserService userService;

    @GetMapping("/select")
    public User selectById(@RequestParam("id") Integer id) {
        return userService.selectById(id);
    }

    @GetMapping("/list")
    public List<User> selectAll() {
        return userService.selectAll();
    }

    @PostMapping("/insert")
    public boolean insert(User user) {
        return userService.insert(user);
    }

    @PostMapping("/update")
    public boolean updateById(User user) {
        return userService.updateById(user);
    }

    @PostMapping("/delete")
    public boolean deleteById(@RequestParam("id") Integer id) {
        return userService.deleteById(id);
    }
}

至此，一个基于Spring Boot和MyBatis Plus框架的MySQL前后端增删改查的完整示例代码就完成了。