Springboot+Mybatis实现最简单的增删改查

以下是一个简单的Spring Boot + MyBatis实现最基本增删改查的示例。

1. 首先，在pom.xml中添加Spring Boot和MyBatis依赖：

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>2.1.4</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <!-- 数据库驱动依赖，以MySQL为例 -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.19</version>
    </dependency>
</dependencies>

2. 配置application.properties或application.yml文件，设置数据库连接信息：

spring.datasource.url=jdbc:mysql://localhost:3306/your_database?useSSL=false&serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=yourpassword
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
mybatis.mapper-locations=classpath:mapper/*.xml

3. 创建一个实体类User：

public class User {
    private Integer id;
    private String name;
    private Integer age;
    // 省略getter和setter方法
}

4. 创建一个Mapper接口UserMapper：

@Mapper
public interface UserMapper {
    int insertUser(User user);
    int deleteUserById(Integer id);
    int updateUser(User user);
    User selectUserById(Integer id);
}

5. 创建对应的Mapper XML文件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">
    <insert id="insertUser" parameterType="User">
        INSERT INTO user(name, age) VALUES (#{name}, #{age})
    </insert>
    <delete id="d