在@ElementCollection上指定主键 [英] Specifying a primary key on @ElementCollection

问题描述

因此，有了Hibernate，我正在寻找一个密钥来指定一个@ElementCollection表上的一个主键，一个Set作为下层数据结构。

我找到了一个有主键和地图的方法，但它是一种奇怪，因为我不需要地图。

我也找到了一个与@Embeddable有关的答案，但我不需要那种复杂性。我在实体中使用Set或Set作为数据结构。

任何想法如何实现？

解决方案

如果您使用Set并使元素Column不为null，则hibernate将使用连接列和元素列创建主键。

示例：

  @Column（name =STRINGS，nullable = false）
 @ ElementCollection 
 private Set< String>串; 
  

So, there is that behavior with innodb that can cause problem if some tables lack of primary key.

So with Hibernate, I am looking for a key to specifies a primary key on a @ElementCollection table with a Set as the underling data structure.

I found a way to have a primary key with a map, but it is kind of weird because I do not need a map.

I also found an answer related to @Embeddable, but I do not need that kind of complexities. I am using a Set or Set as the data structure in my entities.

Any idea how to achieve that?

解决方案

If you use a Set and make the element Column be not null, then hibernate will make a primary key with the join column and element column.

Example:

@Column(name = "STRINGS", nullable = false)
@ElementCollection
private Set<String> strings;

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