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Re: syntax

From: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: kogorman(at)pacbell(dot)net, PGSQL Hackers List <pgsql-hackers(at)hub(dot)org>
Subject: Re: syntax
Date: 2000-10-28 20:54:07
Message-ID: (view raw, whole thread or download thread mbox)
Lists: pgsql-hackers
> Not to put too fine a point on it, but are you talking about the
> original grammar or your modified one?  Your modified one is erroneous
> because it will always associate successive UNION/INTERSECT/EXCEPT
> operators left-to-right; this does not meet the SQL spec which insists
> that INTERSECT binds more tightly than the other two.  Given that, I'm
> not surprised that the precedences have no effect.
> > I don't see precedence in SQL92; set operations
> > seem to be left associative of equal priority.
> Better take another look at the <query expression>, <query term>,
> <query primary> hierarchy then...

Is there something here to patch?  Hmm, I don't see anything...  I will
come back later.  :-)

  Bruce Momjian                        |
  pgman(at)candle(dot)pha(dot)pa(dot)us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

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