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Foreign Key to Primary key relation

debugcn Published at Dev
15
rgx71

I saw a table that has a PK of type int and then a FK that is pointed from the same column to the same column.

For example

Table1
ID int identity
Name nvarchar(50)

ID is the primary key. When I try to see the relations, I see a foreign key from Table1.ID to Table1ID, what does it means?

Heinzi

If that is really a FK from the same field to the same field, it does not make much sense.

However, in general, a FK that references its own table can be useful. Consider the following employee table, for example:

ID int identity
Name nvarchar(50)
SupervisorID int nullable -> FK to ID

SupervisorID can point to another employee and create a hierarchy.

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