JPA在SpringBoot中的使用

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
    </dependency>
    <!-- 其他依赖项 -->
</dependencies>

spring.datasource.url=jdbc:mysql://localhost:3306/database_name
spring.datasource.username=username
spring.datasource.password=password
spring.jpa.generate-ddl=true
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=update

@Entity
@Table(name = "user")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column(name = "name")
    private String name;

    // 其他属性、构造方法、getter/setter方法
}

public interface UserRepository extends JpaRepository<User, Long> {
    // 其他自定义方法
}

@Service
public class UserService {
    @Autowired
    private UserRepository userRepository;

    public List<User> getAllUsers() {
        return userRepository.findAll();
    }

    public User getUserById(Long id) {
        return userRepository.findById(id).orElse(null);
    }

    public User saveUser(User user) {
        return userRepository.save(user);
    }

    public void deleteUser(Long id) {
        userRepository.deleteById(id);
    }
}