Ya mean I have to code this stuff every time I do a delete!!! naa surely
not...There has to be a way...Please!!! Moving from IB to the other one is
like a 2 decade time warp - the wrong way! Is there anything about is good
as IB?

Talk about centralised business rules.

-----Original Message-----
From: Nic Wise <[EMAIL PROTECTED]>
To: Multiple recipients of list database <[EMAIL PROTECTED]>
Date: Monday, 8 November 1999 4:37 PM
Subject: Re: [DUG-DB]: Cascade deletes using Triggers in SQL7 V Interbase


Short answer: you can't. Its an inherant flaw in MS/Sybase SQL Server.
And most others, too - No before + after triggers, only after triggers

Long answer:

begin transaction
--get the PK
delete from childtable where K = thePK

delete from parent where PK = thePK

commit transaction

yes, it IS that painfull.

N

Tony Blomfield wrote:
>
> HI.
>
> With Interbase it is a breeze to do cascade deletes using triggers because
> of IB's concept of New and Old.
>
> With SQL7 it seems nobody thought of this, because the delete is attempted
> BEFORE the trigger is called.
>
> Consider: T1 is parent, T2 is Child with FK constraint to T1
> If I write a simple trigger. The PK for T1 is called T1ID
>
> create trigger DelT1 on T1
>   for delete as
>   declare @T1ID int
> begin
>   /* now casacade */
>
>   select @T1ID = T1IDSecurityGroupID from Deleted;
>   delete from T2 where T2ID = @T1ID;
> end
>
> When I execute Delete from T1 where T1ID = 3
>
> I allways get the FK Constraint Violation, and my delete trigger is not
> called.
>
> QUESTION
>
> How do I get a delete trigger to run before SQL7 actually does the delete,
> or How do others handle cascade deletes in SQL7?
>
> TIA,
>
> Tony.
>
> --------------------------------------------------------------------------
-
>   New Zealand Delphi Users group - Database List - [EMAIL PROTECTED]
>                   Website: http://www.delphi.org.nz

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