相同表中不同项目的Hibernate映射 [英] Hibernate mapping for different items in the same table

问题描述

我有以下三个班级[Promotion, Product and Image]. Promotion具有一个Image. Product具有Image's的列表/集合.将来可能会有新的类也具有Image或Image's的集合.

I have the following three classes [Promotion, Product and Image]. Promotion has an Image. Product has list/collection of Image's. In the future there may be new classes that also has Image or Collection of Image's.

我想将所有图像放在同一张图像表(eg:: image_table)中.这意味着Promotion的图像和Product中的图像集合都将放在同一张表中.

I would like to put all images in the same image table (eg:: image_table). It means that the image of Promotion and the collection of images in Product are all going to go into the same table.

例如，我不能在Image类中放置两个@OneToMany/@ManyToOne注释，因为这样在图像表(eg:: image_table)中将有两个不同的外键(Promotion_FK and Product_FK).将来，如果有更多具有图像的类，那么我必须添加其他@OneToMany/@ManyToOne批注.

I can't put for instance two @OneToMany/@ManyToOne annotations in Image class because then there will be two different foreign keys (Promotion_FK and Product_FK) in Image table (eg:: image_table). In the future if there are more classes that has image then I have to add additional @OneToMany/@ManyToOne annotations.

1. 是否可以在Hibernate中映射此功能?

1. Is there a way to map this feature in Hibernate?

如果我的设计不好，在现实世界中它们如何存储属于不同类的图像?

If my design is not good, in the real world how do they store images that belongs to different classes?

推荐答案

然后尝试使用单向映射

例如 促销具有图片，产品具有图像，但反之亦然

e.g. Promotion having Image, Product having Image's, but not Vice Versa

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