I want to create a constraint that's a little different, but don't know
how to implement it. I have an intermediate table with a compound PK and
a boolean 'ysnDefault' column:
comanyID INTEGER REFERENCES companies,
assocationID INTEGER REFERENCES associations,
ysnDefault BOOLEAN
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.
At first glance I thought it would be easy, but I can't see how to do
it. Any suggestions?
Thanks
Ron