On Wed, Sep 2, 2009 at 3:34 PM, Sam Mason<s...@samason.me.uk> wrote: > On Wed, Sep 02, 2009 at 12:54:03PM -0500, Kevin Grittner wrote: >> Sam Mason <s...@samason.me.uk> wrote: >> > If we did follow Kevin's request directly, should we also be >> > specifying the type of NULL? >> >> I don't *think* the SQL standard requires that, and barring that I >> don't see any compelling reason to type NULL. > > I've just realized that either I'm missing your point entirely (it's > happened before :) or this ignores the point entirely. PG wants to > assign types to every expression, whether this expression will evaluate > to a NULL value at run-time or not is immaterial in this regard. I > think SQL wants to do the same, but I don't have as much conviction as > Tom here. Once we're ascribing types to expressions then whether it > happens to contain the literal "1", "'txt'" or "NULL" we're committed to > giving it some type---the only question is which one. We thus need to > type expressions consisting of just NULL constants. > > A fun puzzle to base any inductive solution on is what type to ascribe > to the following: > > CREATE VIEW v (c) AS > SELECT NULL;
'a of course. ...Robert -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs
