RE: Randomize by Score and DESC
-Original Message- From: Brent Baisley [mailto:[EMAIL PROTECTED] Sent: Saturday, December 06, 2008 11:35 AM To: sangprabv Cc: mos; mysql@lists.mysql.com Subject: Re: Randomize by Score and DESC That's because RAND() is a decimal (0.37689672). Try score*RAND(). [JS] That in itself shouldn't matter. A random number is a random number, regardless of the scale. ORDER BY RAND() is equivalent to ORDER BY myweight*RAND(). As for ordering by score*RAND(), if score comes up 12 and RAND() comes up .1, you will have a product equal to 1.2; if score comes up as 10 and RAND() comes up .2, then you'll have a product equal to 2.0. That is not going to give you what you want. I'm pretty sure what you need to do is come up with a random sample first, and then order the result. SELECT score FROM (SELECT score FROM table WHERE RAND() .1) ORDER BY score DESC; That should give you a random sample of approximately 10% of your original table, in descending order by score. Regards, Jerry Schwartz The Infoshop by Global Information Incorporated 195 Farmington Ave. Farmington, CT 06032 860.674.8796 / FAX: 860.674.8341 www.the-infoshop.com www.giiexpress.com www.etudes-marche.com Brent Baisley On Nov 30, 2008, at 2:03 AM, sangprabv wrote: Hi, Thans for the reply, I have tried it but I don't see the RAND() to be work. This list is always the same. TIA Willy -Original Message- From: mos [EMAIL PROTECTED] To: sangprabv [EMAIL PROTECTED], mysql@lists.mysql.com Subject: Re: Randomize by Score and DESC Date: Sat, 29 Nov 2008 13:05:09 -0600 Mailer: QUALCOMM Windows Eudora Version 6.0.0.22 At 09:15 AM 11/29/2008, sangprabv wrote: Hi, I have a query like this SELECT * FROM table ORDER BY score DESC, RAND() The aim is to randomize the result by score with descending order. But it doesn't work. What missed here? TIA. Willy Willy, That is because you are ordering by Score then Rand. If Score is an integer, try SELECT * FROM table ORDER BY score+RAND() DESC This will randomize the higher scores first, followed by the lower scores etc.. Mike -- 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] infoshop.com -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Randomize by Score and DESC
That's because RAND() is a decimal (0.37689672). Try score*RAND(). Brent Baisley On Nov 30, 2008, at 2:03 AM, sangprabv wrote: Hi, Thans for the reply, I have tried it but I don't see the RAND() to be work. This list is always the same. TIA Willy -Original Message- From: mos [EMAIL PROTECTED] To: sangprabv [EMAIL PROTECTED], mysql@lists.mysql.com Subject: Re: Randomize by Score and DESC Date: Sat, 29 Nov 2008 13:05:09 -0600 Mailer: QUALCOMM Windows Eudora Version 6.0.0.22 At 09:15 AM 11/29/2008, sangprabv wrote: Hi, I have a query like this SELECT * FROM table ORDER BY score DESC, RAND() The aim is to randomize the result by score with descending order. But it doesn't work. What missed here? TIA. Willy Willy, That is because you are ordering by Score then Rand. If Score is an integer, try SELECT * FROM table ORDER BY score+RAND() DESC This will randomize the higher scores first, followed by the lower scores etc.. Mike -- 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]
Re: Randomize by Score and DESC
At 09:15 AM 11/29/2008, sangprabv wrote: Hi, I have a query like this SELECT * FROM table ORDER BY score DESC, RAND() The aim is to randomize the result by score with descending order. But it doesn't work. What missed here? TIA. Willy Willy, That is because you are ordering by Score then Rand. If Score is an integer, try SELECT * FROM table ORDER BY score+RAND() DESC This will randomize the higher scores first, followed by the lower scores etc.. Mike -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Randomize by Score and DESC
Hi, Thans for the reply, I have tried it but I don't see the RAND() to be work. This list is always the same. TIA Willy -Original Message- From: mos [EMAIL PROTECTED] To: sangprabv [EMAIL PROTECTED], mysql@lists.mysql.com Subject: Re: Randomize by Score and DESC Date: Sat, 29 Nov 2008 13:05:09 -0600 Mailer: QUALCOMM Windows Eudora Version 6.0.0.22 At 09:15 AM 11/29/2008, sangprabv wrote: Hi, I have a query like this SELECT * FROM table ORDER BY score DESC, RAND() The aim is to randomize the result by score with descending order. But it doesn't work. What missed here? TIA. Willy Willy, That is because you are ordering by Score then Rand. If Score is an integer, try SELECT * FROM table ORDER BY score+RAND() DESC This will randomize the higher scores first, followed by the lower scores etc.. Mike -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
