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" <[EMAIL PROTECTED]> To: "'Yves Goergen'" <[EMAIL PROTECTED]>; "'Mojtaba Faridzad'" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> 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:[EMAIL PROTECTED] Sent: Tuesday, July 22, 2003 10:26 AM To: Mojtaba Faridzad; [EMAIL PROTECTED] 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" <[EMAIL PROTECTED]> An: <[EMAIL PROTECTED]> 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" <[EMAIL PROTECTED]> > To: "Mojtaba Faridzad" <[EMAIL PROTECTED]> > Cc: <[EMAIL PROTECTED]> > 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/[EMAIL PROTECTED] > > > > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
