Self Referencing Foreign Key?

  • What does this mean if you see it on a table?

    ALTER TABLE [dbo].[Table1] ADD CONSTRAINT [FK_Table1_Column1] FOREIGN KEY ([Column1]) REFERENCES [dbo].[Table1] ([Column1])

    I get why you would might self reference a table but different columns, why the same column?

  • Huh... I'm kind of amazed that works. I just tested it. Not only can you do it, but it doesn't affect inserts or updates. Strange.

    No, I can't imagine why you would do this either. It can't accomplish anything. I just inserted and deleted with no issues.

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  • I noticed the same behavior as well. I thought well maybe if the CASCADE DELETE or UPDATE options were not set it might prevent records from being modified or deleted. Though it worked just fine.

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