Re:database constraints

>We have an application that needs more than a foreign key ,
>the ability to restrict codes to those marked current in
>another table.
>
>This requires a constraint along the lines of
>CONSTRAINT check_current
> CHECK dept_code EXISTS IN ( select d.dept_code
> from division d
> where retired_ind is null )
>
>So the table being defined has a constraint that column
>dept_code must be a current division code (not retired)
>
>Can someone advise when integrity constraints will be extended
>in this direction ?
>
>Stephen Gerard
>
Triggers can do this right now and it doesn't take much more work. Just define a before insert or update of dept_code on row trigger that does this validation. As long as the trigger is enabled on the table the condition must hold.

Ken Levine
Vancouver, BC Received on Thu Jun 16 1994 - 07:55:49 CEST