未识别的关系和外键
如果我有两个未识别的关系，FK_one 和 FK_two。 我不能将它们作为单个主键的唯一方法是当我将 PK 添加到 FK_one 和 FK_two 时，但如果我这样做，关系现在是确定。
所以我的问题是：如果它们是已识别的关系，我只能有两个外键作为 PK，对吗？否则，即使我有两个或多个 FK（未识别的关系），它们也不能用作 PK
if i have two non identified relationships, FK_one and FK_two.
The only way, that i cant put them as a single primary key is when i add PK to the FK_one and FK_two, but if i do that, the relation is now an identified.
So my question is: i can only have two foreign keys as a PK if they are an Identified relationship, correct? otherwise they can't be used as PK even if I have two or more FK (non Identified relationships)
如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱，如果其他用户或者作者回复了您的评论，将不能在第一时间通知您！
发布评论
评论（1）
已识别的关系是用 2 个或更多 FK 作为主键且没有代理键来“识别”的。因此，您最终会得到一个组合主键，但据我所知，您可以拥有所需的所有主键，但这对服务器性能不利。
An identified relationship is "identified" with 2 or more FKs as primary keys and without a surrogate key. So you end up with a composed primary key, but as far as I know you can have all the primary keys you want but that's not good for the server performance.