> On Mon, Jul 25, 2005 at 06:11:08PM -0300, Marc G. Fournier wrote: > > > > Just curious as to whether or not a warning or something should be issued > > in a case like: > > > > SELECT c.* > > FROM company c, company_summary cs > > WHERE c.id = cs.id > > AND cs.detail = 'test' > > ORDER BY cs.fullname; > > > > Unless I'm missing something, the ORDER BY clause has no effect, but an > > EXPLAIN shows it does take extra time, obviously ... > > Uh, I'd hope it had an effect. Note that RDBMSes have been moving > towards allowing fields in ORDER BY that aren't in the SELECT list, > though in the past it was common that anything in ORDER BY had to also > be in SELECT.
Prior to SQL:1999, the spec required that any column referenced in an ORDER BY clause must also be referenced in the SELECT. SQL:1999 (feature E1210-02) relaxed this to allow columns to be specified in the ORDER BY clause but not in the SELECT. -- Matt Emmerton ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
