Re: Making ORDER BY RAND() more random [resend]
change the seed on the random function. http://dev.mysql.com/doc/mysql/en/mathematical-functions.html On Mon, 2005-10-03 at 08:33 -0700, Graham Anderson wrote: is there a way to make ORDER BY RAND() at bit more spontaneous ? I am using it in a php statement: $sql = SELECT media.id, artist.name as artist, artist.spanish as bio, artist.purchaseLink, artist.picture, media.spanish as trackName, media.path, media.quality, mediaType.id as mediaType FROM artist, media, playlistItems, mediaType WHERE playlistItems.playlist_id = $myID AND playlistItems.media_id = media.id AND media.artist_id = artist.id AND media.mediaType_id = mediaType.id ORDER BY RAND() LIMIT 0, 30; the result seems to be pretty predictable is there a way to improve RAND() or is there something better ? Should I be using php to randomize the found set instead ? many thanks g -- 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: Making ORDER BY RAND() more random [resend]
Graham Anderson wrote: is there a way to make ORDER BY RAND() a bit more spontaneous ? I am using it in a php statement: $sql = SELECT media.id, artist.name as artist, artist.spanish as bio, artist.purchaseLink, artist.picture, media.spanish as trackName, media.path, media.quality, mediaType.id as mediaType FROM artist, media, playlistItems, mediaType WHERE playlistItems.playlist_id = $myID AND playlistItems.media_id = media.id AND media.artist_id = artist.id AND media.mediaType_id = mediaType.id ORDER BY RAND() LIMIT 0, 30; the result seems to be pretty predictable is there a way to improve RAND() or is there something better ? Should I be using php to randomize the found set instead ? many thanks g I don't think anyone can answer this, as is. RAND() is meant to produce a pseudo-random sequence that is not truly random in the mathematical sense, but which is usually good enough for what you appear to be doing. The manual http://dev.mysql.com/doc/mysql/en/mathematical-functions.html puts it this way, RAND() is not meant to be a perfect random generator, but instead a fast way to generate ad hoc random numbers that is portable between platforms for the same MySQL version. What is your standard for randomness? What do you mean by the result seems to be pretty predictable? Put another way, what are you expecting, and what are you getting? Michael -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Making ORDER BY RAND() more random [resend]
In the below query, the results first row is usually the same 3-4 tracks out of 30. so should I use PHP to generate a random seed, $r, and pass that to the query ? ORDER BY RAND($r) or, can it be done just with mysql many thanks g On Oct 3, 2005, at 10:15 AM, Michael Stassen wrote: Graham Anderson wrote: is there a way to make ORDER BY RAND() a bit more spontaneous ? I am using it in a php statement: $sql = SELECT media.id, artist.name as artist, artist.spanish as bio, artist.purchaseLink, artist.picture, media.spanish as trackName, media.path, media.quality, mediaType.id as mediaType FROM artist, media, playlistItems, mediaType WHERE playlistItems.playlist_id = $myID AND playlistItems.media_id = media.id AND media.artist_id = artist.id AND media.mediaType_id = mediaType.id ORDER BY RAND() LIMIT 0, 30; the result seems to be pretty predictable is there a way to improve RAND() or is there something better ? Should I be using php to randomize the found set instead ? many thanks g I don't think anyone can answer this, as is. RAND() is meant to produce a pseudo-random sequence that is not truly random in the mathematical sense, but which is usually good enough for what you appear to be doing. The manual http://dev.mysql.com/doc/mysql/en/mathematical-functions.html puts it this way, RAND() is not meant to be a perfect random generator, but instead a fast way to generate ad hoc random numbers that is portable between platforms for the same MySQL version. What is your standard for randomness? What do you mean by the result seems to be pretty predictable? Put another way, what are you expecting, and what are you getting? Michael -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
