Re: Can I have check and referential constraint on same column?

[Charles Wilt <charles.wilt@xxxxxxxxx>]

the blank could be handled if instead of blank you allowed NULLs

That wouldn't help with the V however.

You could handle both V and blank with a before trigger

HTH,
Charles


On Thu, May 20, 2010 at 3:40 PM,  <Rick.Chevalier@xxxxxxxxxxxxxxx> wrote:
> I can add the constraints but it doesn't do what I need it to.  I have a check constraint of 'V' or blank and a referential constraint of 'P' or 'H' (more to come later).  The 'V' and blank are hard coded into the program depending on certain conditions.  If the user chooses an override the 'P' or 'H' will be used.  Unfortunately they appear to be mutually exclusive.
>
> I tried inserting a row using SQL and if I use one of the referential constraint values the insert fails due to the check constraint.  If I use one of the check constraint values the insert fails due to the referential constraint.  The value has to satisfy both constraints.
>
> It makes sense, it just doesn't work for me in this case.
>
> Rick
>
> -----Original Message-----
> From: midrange-l-bounces@xxxxxxxxxxxx [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Luis Rodriguez
> Sent: Thursday, May 20, 2010 1:49 PM
> To: Midrange Systems Technical Discussion
> Subject: Re: Can I have check and referential constraint on same column?
>
> Rick,
>
> To check my answer I did a small test:
>
> ALTER TABLE MyLib/File1
>  ADD Constraint FK_CardType
>      FOREIGN KEY (CardType)
>      REFERENCES  MyLib/File2 (CardType) ;
>
> ALTER TABLE File1 ADD CHECK (CardType <> 9 ) ;
>
> No problem in creating both constraints. Even if there is a CARDTYPE 9 in File2, I can't insert a CARDTYPE 9 record in File1. The system returns CPF502F (Check constraint violation).
>
> Did not check what happens the CHECK constraint is created before the foreign key...
>
> HTH,
> Luis Rodriguez
> IBM Certified Systems Expert - eServer i5 iSeries
>
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