At 05:39 PM 2/13/2011, Andre Polykanine wrote:
Hi all, Hope this question is appropriate here :-). I've got 4 queries:$q1=mysql_query("SELECT * FROM `CandidateQuestions` WHERE `Category`='1' ORDER BY RAND() LIMIT 1"); $q2=mysql_query("SELECT * FROM `CandidateQuestions` WHERE `Category`='2' ORDER BY RAND() LIMIT 1"); $q3=mysql_query("SELECT * FROM `CandidateQuestions` WHERE `Category`='3' ORDER BY RAND() LIMIT 1"); $q4=mysql_query("SELECT * FROM `CandidateQuestions` WHERE `Category`='4' ORDER BY RAND() LIMIT 1"); What I need is to select exactly 4 questions so that each of them would be randomly selected from each category. Note: I don't need 4 *any* questions, I need 1 question from the 1st category, 1 question from the 2nd category etc. Is there a way to make one query for this? If I do "SELECT * FROM `CandidateQuestions` WHERE `Category` IN (1,2,3,4) GROUP BY `Category` LIMIT 4", I think i would get 4 random questions, wouldn't I?
Correct. You could use: SELECT * FROM `CandidateQuestions` WHERE `Category`='1' ORDER BY RAND() LIMIT 1 union SELECT * FROM `CandidateQuestions` WHERE `Category`='2' ORDER BY RAND() LIMIT 1 union SELECT * FROM `CandidateQuestions` WHERE `Category`='3' ORDER BY RAND() LIMIT 1 union SELECT * FROM `CandidateQuestions` WHERE `Category`='4' ORDER BY RAND() LIMIT 1 and this returns 4 rows, with 1 random record from each category. Mike
Thanks in advance! -- With best regards from Ukraine, Andre Skype: Francophile Twitter: http://twitter.com/m_elensule Facebook: http://facebook.com/menelion -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=mo...@fastmail.fm
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