一个表中的多个外键到另一个表中的单个主键是否可以？
假设我有两个表
Products 表：
|ProductID|ProductName|ListPrice|
PrebuiltSystems 表：
|BuldID|Processor|Motherboard|RAM|
处理器、主板等的值都是现有的ProductID。我现在正在创建 从每个部件名称列到一个 ProductID 的外键关系，并为每个部件创建一堆导航属性和关系行。这样可以吗？
或者是否有某种关系合并/规则，我可以用它来表示所有这些列都是 productID 的外键，而无需创建一对一的关系？
Say I have two tables
Products table:
|ProductID|ProductName|ListPrice|
PrebuiltSystems table:
|BuldID|Processor|Motherboard|RAM|
The values for the Processor, Motherboard etc. are all existing ProductID's. I am now creating
foreign key relationships from each of the part name columns to the one ProductID and have a bunch of navigation properties and relationships lines being created for each part. Is this ok?
Or is there some kind of relationship merger/rule that I can use to say all those columns are foreign keys to productID without creating one to one relationships ?
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是的，这是正确的做法。
不，它们都是不同的关系。
请注意，这些是多对一关系，而不是一对一关系，许多
PrebuiltSystems将具有相同的处理器< /代码>Yes, this is the right way to do it.
No, they are all different relationships.
Note that these are many-to-one, not one-to-one relationships, many
PrebuiltSystemswill have the sameProcessor是的，有多个外键是可以的。然而，在你的例子中，我仍然会采取不同的做法；如果每种组件类型都只有一列，那么您就会受到很大的限制。你用多CPU系统做什么？多个硬盘等怎么办？
您应该规范化 PrebuiltSystems 表，以便拥有一个链接表，该链接表创建与产品的 n 对 n 关系（例如，每个产品可以是任意数量的预构建系统的一部分，并且每个预构建系统可以有任意数量的产品在其中）。
Yes it is fine to have multiple foreign keys. However, in your example, I'd still do it differently; if you have one column for each component type you limit yourself very much. What do you do with a multi-CPU-system? What with multiple harddisks etc.?
You should rather normalize the PrebuiltSystems table so that you have a link table which creates a n-to-n relationship to the products (e.g. each product can be part of any number of prebuilt systems, and each prebuilt system can have any number of products in it).