Re: Hierarchy as 'UP' constraint

I forgot to add "INSTEAD OF INSERT and INSTEAD OF UPDATE are left as an exercise for the reader." :-)

"x" <x_at_not-exists.org> wrote in message news:dm6sjd$bad$1_at_domitilla.aioe.org...
> Foreign key on pnr + instead of trigger in SQL Server
>
>
> CREATE TRIGGER treenodes_delete
> ON treenodes
> instead of delete
> AS
> DECLARE _at_RowCount INT
> repet:
> update treenodes
> set pnr=(select pnr from deleted where deleted.nr=treenodes.pnr)
> where exists (select * from deleted where deleted.nr=treenodes.pnr);
>
> SELECT _at_RowCount = @@ROWCOUNT ;
>
> if _at_RowCount>0
> goto repet ;
>
> delete treenodes
> from treenodes t, deleted d
> where t.nr=d.nr;
>
> This needs some changes to cope with various root encodings.
> How this would perform on large tables ?
>
>
Received on Fri Nov 25 2005 - 13:13:20 CET