用SpringBoot整合mybatis实现简单增删改查操作的代码

好的，以下是使用SpringBoot整合mybatis实现简单增删改查操作的代码示例：

1. 首先在pom.xml中添加依赖：

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.4</version>
</dependency>

2. 在application.properties中配置数据库相关信息：

# 数据库配置
spring.datasource.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

# Mybatis配置
mybatis.mapper-locations=classpath*:mapper/*.xml
mybatis.type-aliases-package=com.example.demo.entity

3. 创建实体类和Mapper接口：

// User实体类
public class User {
    private Long id;
    private String name;
    private Integer age;

    // getter和setter方法省略
}

// UserMapper接口
public interface UserMapper {
    User selectById(Long id);
    List<User> selectAll();
    void insert(User user);
    void update(User user);
    void delete(Long id);
}

4. 在resources/mapper目录下创建UserMapper.xml文件，定义SQL语句：

<?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" jdbcType="BIGINT" />
        <result column="name" property="name" jdbcType="VARCHAR" />
        <result column="age" property="age" jdbcType="INTEGER" />
    </resultMap>

    <select id="selectById" resultMap="BaseResultMap">
        SELECT id, name, age FROM user WHERE id = #{id}
    </select>

    <select id="selectAll" resultMap="BaseResultMap">
        SELECT id, name, age FROM user
    </select>

    <insert id="insert">
        INSERT INTO user (name, age) VALUES (#{name}, #{age})
    </insert>

    <update id="update">
        UPDATE user SET name = #{name}, age = #{age} WHERE id = #{id}
    </update>

    <delete id="delete">
        DELETE FROM user WHERE id = #{id}
    </delete>
</mapper>

5. 在Service中调用Mapper接口：

@Service
public class UserService {
    @Autowired
    private UserMapper userMapper;

    public User getUserById(Long id) {
        return userMapper.selectById(id);
    }

    public List<User> getAllUser() {
        return userMapper.selectAll();
    }

    public void addUser(User user) {
        userMapper.insert(user);
    }

    public void updateUser(User user) {
        userMapper.update(user);
    }

    public void deleteUser(Long id) {
        userMapper.delete(id);
    }
}

最后，启动应用程序即可进行增删改查操作。