package com.example.demo;

import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface EmailRepository extends CrudRepository<Email, Long> {
}



package com.example.demo;

import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface MessageRepository extends CrudRepository<Message, Long>{
}



@Controller
@RequiredArgsConstructor
public class DemoController {

    @Autowired
    private MessageRepository messageRepository;

    @Autowired
    private EmailRepository emailRepository;

    Message message = new Message().setContent("Broken");
    messageRepository.save(message);

    Email email = new Email().setSubject("Subject 0").setMessage(message);
    emailRepository.save(email);


    Email email1 = new Email().setSubject("Subject 1").setMessage(message);

    Optional em = messageRepository.findById(1L);
    int a = 0;

}