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From:Mojtaba Faridzad Date:July 22 2003 2:45pm
Subject:Re: how to limit COUNT(*)
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at least on MyISAM table doesn't work. even it worked, still mysql should
have counted all possible records and then found the max.

If you check the manual, somebody on 2nd of October 2002 had the same
question but nobody answered to it.
http://www.mysql.com/doc/en/Counting_rows.html


----- Original Message ----- 
From: "Mike Brum" <php@stripped>
To: "'Yves Goergen'" <nospam.list@stripped>; "'Mojtaba Faridzad'"
<mfaridzad@stripped>; <mysql@stripped>
Sent: Tuesday, July 22, 2003 10:34 AM
Subject: RE: how to limit COUNT(*)


Would that help at all - since the COUNT(*) would execute fully and then
MAX would limit it? (or is the order of operations different than that?)

-M

-----Original Message-----
From: Yves Goergen [mailto:nospam.list@stripped]
Sent: Tuesday, July 22, 2003 10:26 AM
To: Mojtaba Faridzad; mysql@stripped
Subject: Re: how to limit COUNT(*)


a LIMIT will not work in any case with COUNT since you will always get
exactly one row. and what shall a LIMIT 10000 on 1 row do here?

but you can try the MAX function here: (i guess it exists :)

SELECT MAX(COUNT(*), 10001) as numfound FROM mytable WHERE mycond;

-yves


-----Ursprüngliche Nachricht----- 
Von: "Mojtaba Faridzad" <mfaridzad@stripped>
An: <mysql@stripped>
Gesendet: Dienstag, 22. Juli 2003 15:40
Betreff: Re: how to limit COUNT(*)


> for example:
>
> SELECT COUNT(*) as numfound FROM mytable WHERE mycondition;
>
> in this query, mytable and mycondition are variable and on run time,
> they are changed. I use this query to jump to the last page of a grid
> form. sometimes the query may have more than million records and I
> want to give a warning to the user to specify a condition to limit the

> number of records. I would like to count the records upto 10000 (for
> example) and if the records are more than this, stop counting and ask
> user to change the condition. to solve this problem I did something
> like this:
>
> SELECT one_field FROM mytable WHERE mycondition LIMIT 10001;
>
> if the number of records of this query is equal to 10001, then I show
> the warning message. but this query is not as fast of COUNT query. is
> there any way to limit the first query?
>
> thanks
>
> ----- Original Message -----
> From: "gerald_clark" <gerald_clark@stripped>
> To: "Mojtaba Faridzad" <mfaridzad@stripped>
> Cc: <mysql@stripped>
> Sent: Tuesday, July 22, 2003 9:15 AM
> Subject: Re: how to limit COUNT(*)
>
>
> > Perhaps you could post some examples of what you have tried. I don't

> > understand what you are asking.
> >
> > Mojtaba Faridzad wrote:
> >
> > >Hi,
> > >
> > >I guess there is no way to limit COUNT(*). Is that right? We cannot

> > >use
> the
> > >result of COUNT in WHERE condition or LIMIT doesn't help. In this
> > >case so far I have retrieved a field and used LIMIT. Is there a
> > >better way to control it?
> > >
> > >Thanks
> > >
> > >
> > >
> > >
> >
> >
> >
> > --
> > MySQL General Mailing List
> > For list archives: http://lists.mysql.com/mysql
> > To unsubscribe:
> http://lists.mysql.com/mysql?unsub=1
> >
>
>
> --
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Thread
Odd thingDave Christensen19 Jun
  • Re: Odd thingDon Read19 Jun
RE: Odd thingJay Blanchard19 Jun
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RE: Odd thingJay Blanchard19 Jun
RE: Odd thingDallas Dickey19 Jun
  • selecting PRIMARY KEY when there is no unique valueMojtaba Faridzad19 Jun
    • Re: selecting PRIMARY KEY when there is no unique valueBruce Feist19 Jun
    • Re: selecting PRIMARY KEY when there is no unique valuePaul DuBois19 Jun
    • Re: selecting PRIMARY KEY when there is no unique valueDon Read19 Jun
  • Re: selecting PRIMARY KEY when there is no unique valuePeterWR19 Jun
  • Re: selecting PRIMARY KEY when there is no unique valueMichael Conlen19 Jun
  • Re: selecting PRIMARY KEY when there is no unique valueMojtaba Faridzad19 Jun
  • Re: selecting PRIMARY KEY when there is no unique valueKen Menzel19 Jun
  • how to limit COUNT(*)Mojtaba Faridzad22 Jul
  • Re: how to limit COUNT(*)gerald_clark22 Jul
  • Re: how to limit COUNT(*)Jerry22 Jul
  • Re: how to limit COUNT(*)Mojtaba Faridzad22 Jul
    • Re: how to limit COUNT(*)Fred van Engen22 Jul
  • Re: how to limit COUNT(*)Viorel Dragomir22 Jul
  • Re: how to limit COUNT(*)Mojtaba Faridzad22 Jul
  • Re: how to limit COUNT(*)Yves Goergen22 Jul
    • RE: how to limit COUNT(*)Mike Brum22 Jul
      • Re: how to limit COUNT(*)Mojtaba Faridzad22 Jul
  • Re: how to limit COUNT(*)gerald_clark22 Jul
    • Re: how to limit COUNT(*)Keith C. Ivey22 Jul
  • Re: how to limit COUNT(*)Mojtaba Faridzad22 Jul
    • Re: how to limit COUNT(*)Fred van Engen22 Jul
RE: Odd thingDallas Dickey19 Jun
RE: Odd thingJay Blanchard19 Jun
RE: Odd thingDave Christensen19 Jun
RE: selecting PRIMARY KEY when there is no unique valueMike Hillyer19 Jun
RE: Odd thingDave Christensen19 Jun
RE: Odd thingDave Christensen19 Jun
RE: Odd thingDave Christensen19 Jun
  • Re: Odd thinggerald_clark19 Jun
RE: Odd thingDave Christensen19 Jun