[Spring] @ManyToOne 어노테이션 4 회원가입

1. View 확인

import lombok.Data;

public class UserRequest {

    @Data
    public static class JoinDTO{
        private String username;
        private String password;
        private String email;

				//INSERT 시에만 사용
        public User toEntity(){
            return User.builder()
                    .username(username)
                    .password(password)
                    .email(email)
                    .build();
        }
    }

2. 컨트롤러

    @PostMapping("/join")
    public String join(UserRequest.JoinDTO requestDTO){
        userRepository.save(requestDTO.toEntity());

        return "redirect:/login-form";
    }

3. 레파지토리

    @Transactional
    public void save(User user) {
		   em.persist(user);

    }