Mike Fowler <mike@mlfowler.com> wrote:
> So to summarise, Oracle and PostgreSQL need minor tweaks to run
> cleanly and SQLServer and MySQL do not.
The FROM DUAL in Oracle has nothing to do with the issue at hand.
That is just because they always require a FROM clause on every
SELECT. DUAL is a special table with one row you can use when you
just want to select a literal.
That means that all three of the databases you tested have
extensions to the standard similar to what is being contemplated for
PostgreSQL. If nothing else, adding such an extension would ease
migration from those other products, but I think it would prevent
some user confusion and posts to the -bugs list, too.
-Kevin