Re: Check constraint

On Wednesday 17 March 2004 12:03, Francisco Reyes wrote:
> I have a "comment" field in a table that I want populated if another field
> has a certain value. Is it possible to set a check constraint for this?
>
> Example:
> Let's say we have fields
> Purchase_type smallint check(purchase_type <4)
> comment       varchar
>
> I need a check rule to something like (pseudo code)
> check (if purchase_type = 3 then NOT NULL comment)

No - you'll want a BEFORE UPDATE/INSERT trigger. It shouldn't be difficult to
do though.

--
  Richard Huxton
  Archonet Ltd