MS SQL “ON DELETE CASCADE” multiple foreign keys pointing to the same table?

Question

I have a problem where i need a cascade on multiple foreign keys pointing to the same table..

[Insights]
| ID | Title        |
| 1  | Monty Python |
| 2  | S         


        

Answer 1

You'll have to implement this as an INSTEAD OF delete trigger on insights, to get it to work. Something like:

create trigger T_Insights_D
on Insights
instead of delete
as
    set nocount on
    delete from broader_insights_insights
    where insight_id in (select ID from deleted) or
    broader_insight_id in (select ID from deleted)

    delete from Insights where ID in (select ID from deleted)

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Frequently with cascading deletes and lots of foreign keys, you need to spend time to work out a "cascade" order so that the delete that occurs at the top of a "tree" is successfully cascaded to referencing tables. But that isn't possible in this case.