스프링 Entity N대 1 관계

• @ManyToOne

  • @ManyToOne 애너테이션은 N 대 1 관계를 맺어주는 역할.

    

@Entity
@Table(name = "food")
public class Food {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;
    private double price;

    @ManyToOne
    @JoinColumn(name = "user_id")
    private User user;
}

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

@Entity
@Table(name = "food")
public class Food {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;
    private double price;

    @ManyToOne
    @JoinColumn(name = "user_id")
    private User user;
}

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

    @OneToMany(mappedBy = "user")
    private List<Food> foodList = new ArrayList<>();
}

List 형태로 Food 를 담고있는걸 확인하자