Re: primary key on lower(varchar)

<me@alternize.com> writes:
> why can't i define a primary key on a varchar field as being
> lower(field)?

Primary keys are only on simple field values; that's what the SQL
standard requires, and that's what we do.

I don't really see the use-case for what you want anyway.  Why don't
you just require the field to be all lower case, eg with a CHECK
constraint?

            regards, tom lane