使用结点表的JPA I:N和1:1 [英] JPA I:N and 1:1 using Junction table

问题描述

JPA问题:我正在尝试使用联结表(Person_Address)对1:N(人与地址)关系进行建模.

JPA Question: I am trying to model 1:N (Person & Address) relationship using a junction table (Person_Address).

1. 人(personId PK)

1. Person (personId PK)

地址(addressId PK)

Address (addressId PK)

PersonAddress( personId，addressId复合PK， personId FK引用Person， addressid FK引用地址)

PersonAddress ( personId, addressId composite PK, personId FK references Person, addressid FK references Address)

如何映射这些关系?加载Person对象时如何加载地址列表?

How to map these relationships? How to load list of addresses when Person object is loaded?

推荐答案

您正在描述一个OneToMany关系，该关系通常不需要联接表.您仅在多"一面有一个引用一"面的字段.

You're describing a OneToMany relationship which typically does not require a join table. You just have a field on the Many side that references the One side.

但是，如果您确实想做自己正在做的事情，那么这应该可行:

However, if you really want to do what you're doing, then this should work:

@Entity
public class Person {

...

  @OneToMany
  @JoinTable(
    name="PersonAddress",
    joinColumns = @JoinColumn( name="personId"),
    inverseJoinColumns = @JoinColumn( name="addressId")
   )
  public Set<Address> getAddresses() {...}

...
}

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