Re: protected ON DELETE CASCADE

Murray Hobbs wrote:
>
>here's my problem
>
>i have tables A, B, C, D
>
>A <- B
>A <- C <- D
>
>i want to maintain integrity so that if A is deleted from then so is
>anything referencing from B and C - no problem ON DELETE CASCADE
>
>but if there are any D's that point back to A (through composite key in
>C) i don't want the delete to go ahead - at all - i want an error
>message and condition

If the reference from D to C uses ON DELETE RESTRICT (or NO ACTION), that
should fail and thus cause the original DELETE to fail.

--
Oliver Elphick Oliver(dot)Elphick(at)lfix(dot)co(dot)uk
Isle of Wight http://www.lfix.co.uk/oliver
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