Re: Constraint Problem

Tom Lane wrote:

>Ron St-Pierre <rstpierre@syscor.com> writes:
>
>
>>I just want to constrain the ysnDefault field to only allow one TRUE
>>value for any companyID/associationID pair, with no restrictions on the
>>number of FALSES.
>>
>>
>
>You could do that with a partial unique index.  There is an example
>at the bottom of
>http://www.postgresql.org/docs/7.3/static/indexes-partial.html
>
>            regards, tom lane
>
>---------------------------(end of broadcast)---------------------------
>TIP 5: Have you checked our extensive FAQ?
>
>               http://www.postgresql.org/docs/faqs/FAQ.html
>
>
>
>
This is not quite what I need. I need to create a constraint to allow
only -one- of
    company<->association<->default(=true) value
but any number of
    company<->association<->default(=false) values

I've tried many different ALTER TABLE ... CREATE CONSTRAINT variations,
all without success.

Anyone know how?

Thanks
Ron