spring boot使用mysql访问数据

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.27</version>
</dependency>

spring.datasource.url=jdbc:mysql://localhost:3306/mydatabase
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

@Repository
public interface UserRepository extends JpaRepository<User, Long> {
}

@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 createUser(User user) {
        return userRepository.save(user);
    }
    
    public void deleteUser(Long id) {
        userRepository.deleteById(id);
    }
}

@RestController
public class UserController {
    @Autowired
    private UserService userService;
    
    @GetMapping("/users")
    public List<User> getAllUsers() {
        return userService.getAllUsers();
    }
    
    @GetMapping("/users/{id}")
    public User getUserById(@PathVariable Long id) {
        return userService.getUserById(id);
    }
    
    @PostMapping("/users")
    public User createUser(@RequestBody User user) {
        return userService.createUser(user);
    }
    
    @DeleteMapping("/users/{id}")
    public void deleteUser(@PathVariable Long id) {
        userService.deleteUser(id);
    }
}