> %--
> %--> Dear sir,
> %--> 
> %--> Just one remark for your book :
> %--> in your chapter "SQL Aggregates", it is interessant perhaps if you
> %--> say if COUNT(DISTINCT ...) for example is supported. 
> %--> 
> %--> mb
> %--> 
> %--
> %--It isn't supported.
> %--
> 
> Sorry, I just want to say "It is not supported" obviously. I think, it is 
> important to say it, because I search for my mistake a little bit before
> finding the answer in the FAQ.

CC to hackers.

The best way to do that is to display a mess to the user when they try
COUNT(DISTINCT...).   That makes it easy because they see it as soon as
they try it.  No hunting around, but I am not sure how to do that in the
grammer because we don't find out about aggregates until later.


-- 
  Bruce Momjian                        |  http://www.op.net/~candle
  maillist@candle.pha.pa.us            |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Mon, 6 Dec 1999 22:27:22 -0500 (EST)
Bruce Momjian <pgman@candle.pha.pa.us>
Re: Book - SQL Aggregates
Bruce Momjian <pgman@candle.pha.pa.us> writes:
> The best way to do that is to display a mess to the user when they try
> COUNT(DISTINCT...).   That makes it easy because they see it as soon as
> they try it.

I was actually thinking about trying to implement aggregate(DISTINCT ...),
or failing that, at least understand why it's hard ;-)

At the very least I think I can manage an explicit "DISTINCT not supported"
error message from the parser.  Will take this as a TODO item.

			regards, tom lane

Mon, 06 Dec 1999 23:29:54 -0500
Tom Lane <tgl@sss.pgh.pa.us>
Re: [HACKERS] Re: Book - SQL Aggregates 