超级键和复合键之间的差异 [英] Difference between super key and composite key

问题描述

我需要了解超级键和复合键之间的区别。我发现的例子更加困惑。你能简单地澄清有什么区别？感谢

I need to understand the difference between super key and composite key. The examples I found made more confused. Can you please simply clarify what is the difference? Thanks

推荐答案

超级键唯一标识一行。它可以由一列或多列组成。复合键是由多个列组成的键。

A super key uniquely identifies a row. It could be made up of one column or many. A composite key is a key made of more than one column.

如果超级键由多个列组成，它也是一个复合。

If a Super Key is made of more than one column it is also a composite.

键唯一标识一行它也是一个超级键。

If a composite key uniquely identifies a row it is also a Super key.

我看不到名称'超级键'使用太多：它通常只被称为'唯一键'。

I don't see the name 'Super key' used too much: it's usually just called a 'Unique key'.

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