Re: Constraint Problem

Tom Lane wrote:

>Ron St-Pierre  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
>
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>  
>
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