外键和引用键有什么区别？ [英] What is difference between foreign key and reference key?

问题描述

这两者之间我很困惑。他们是相同还是不同？有些书或人说他们是一样的，有些则说他们不一样。我试过，但没有找到任何真实的答案。

请大家解决它。

解决方案

我假设你正在讨论使用 REFERENCES where FOREIGN KEY 关键字不被使用，例如。

  author_id INTEGER REFERENCES作者（id）
  

...而不是...

  author_id INTEGER，
 FOREIGN KEY（author_id）REFERENCES作者（id）
  

答案是，它只是同一事物的简写语法。两者之间的主要关切应该是可读性的。

I am very confused between these two. Are they same or different? Some books or people says they are same and others says they are different. I tried but not find any authentic answer.
Please guys solve it.

解决方案

I am supposing that you are talking about using the REFERENCES where the FOREIGN KEY keyword is not used, eg.

author_id INTEGER REFERENCES author(id)

... instead of ...

author_id INTEGER,
FOREIGN KEY(author_id) REFERENCES author(id)

The answer is, that it is simply shorthand syntax for the same thing. The main concern when altering between the two should be readability.

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