Re: Comma-separated predicates in simple CASE expressions (f263)

Daniel Gustafsson <daniel(at)yesql(dot)se> writes:
> I was looking at F263 from the SQL standard, Comma-separated predicates in
> simple CASE expression, and thinking if we could support this within the
> framework we already have at a minimal added cost. The attached sketch diff
> turns each predicate in the list into a CaseWhen node and uses the location
> from parsing for grouping in errorhandling for searched case.

> Is this a viable approach or am I missing something obvious?

I don't particularly like duplicating the THEN clause multiple times.
I think if we're going to do this we should do it right, and that
means a substantially larger patch to propagate the notion of multiple
comparison values all the way down.

I also don't care for the bit in transformCaseExpr where you seem
to be relying on subexpression location fields to make semantic
decisions. Surely there's a better way.

regards, tom lane