如何在没有@Id的情况下使用spring Repository?
我在整个应用程序中使用 spring CrudRepository.现在我还想为没有 @Id 的 @Entity 创建一个.这可能吗?
I'm using spring CrudRepository throughout my application.
Now I want to also create one for an @Entity that does not have an @Id. Is that possible at all?
//probably ID is always required?
public interface Repository<T, ID extends Serializable>
推荐答案
JPA 要求每个实体都有一个 ID.所以不，不允许没有 ID 的实体.
JPA requires that every entity has an ID. So no, entity w/o an ID is not allowed.
每个 JPA 实体都必须有一个主键.
Every JPA entity must have a primary key.
来自 JPA 规范
您可能想了解更多关于当数据库端没有 id 时 JPA 如何处理案例 从这里(参见无主键").
You may want to read more about how JPA handles a case when there's no id on the DB side from here (see 'No Primary Key').
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