如何在 Spring 数据 JPA 中为以下场景创建实体关系？

Question

@Entity
public class A {
 @column("ID")
 private Long id;
}

@Entity
public class B {
 @column("ID")
 private Long id;
}

@Entity
public class C {
 @column("ID")
 private Long id;

 @column("A_ID")
 private Long aID;

 @column("B_ID")
 private Long bID;
}

在 C 实体中以下插入是可能的

ID A_ID  B_ID
 1   1     1
 2   2     1
 3   3     1
 4   1     2
 5   2     2
 6   3     2

在上述情况下，我想从子实体 (C) 获取父实体 (A 或 B)

例如

C c=crepository.findByID(6);
A a=c.getA();
B b=c.getB();

如何在上述实体中创建关系？我希望使用 Spring 数据 JPA 可以实现。

Answer 1

像这样利用 @OneToOne 注释应该做到这一点：

@Entity
public class A {
    @Column("ID")
    private Long id;

    //other columns, getters, and setters
}

@Entity
public class B {
    @Column("ID")
    private Long id;

    //other columns, getters, and setters
}

@Entity
public class C {
    @column("ID")
    private Long id;

    @OneToOne
    @JoinColumn(name = "A_ID", referencedColumnName  = "ID")
    private A a;

    @OneToOne
    @JoinColumn(name = "B_ID", referencedColumnName  = "ID")
    private B b;

    //other columns, getters, and setters
}

如何在 Spring 数据 JPA 中为以下场景创建实体关系？

How to create entity relationship for following scenario in Spring data JPA?

hibernate

spring-data-jpa