I rewrote my line using your suggestion ... select id,first,middle,last from persons order by rand() limit 10;
and it worked perfectly. I'm still curious about why my original version gave such cockeyed results, but I'll focus on the successful solution and leave that unsolved problem for another day. Thank you for your solution Michael. On Sun, 2007-04-29 at 08:48 -0400, Michael Dykman wrote: > If might suggest: > > SELECT * FROM BAR > ORDER BY RAND() > LIMIT 10 > > On 4/29/07, John Kebbel <[EMAIL PROTECTED]> wrote: > > For possible educational research purposes, I was playing around with a > > query that would randomly select people from a database. The database I > > experiment with has a group of fictitious persons with id numbers > > (primary key) ranging sequentially from 2 to 378. When I ran these > > queries below, I was expecting to select five random persons from the > > database. The query partially worked. I was getting random subjects, but > > everytime I ran the query, I got a different number of subjects, > > stretching from 0 and up (sometimes as many as 8 or 9). I could see the > > query generating fewer rows if I duplicated an id or made an off-by-one > > error, but I don't see how it could generate more than five. Does anyone > > see my error? (I've used two equivalent forms for the query below; both > > did the same thing) > > > > select id,first,middle,last from persons where id = ceil(rand()*377+1) > > or id = ceil(rand()*377+1) or id = ceil(rand()*377+1) or id = > > ceil(rand()*377+1) or id = ceil(rand()*377+1); > > > > select id,first,middle,last from persons where id in (ceil(rand()*377 > > +1), ceil(rand()*377+1), ceil(rand()*377+1), ceil(rand()*377+1), > > ceil(rand()*377+1)); > > +------+-------------+--------+----------+ > > | id | first | middle | last | > > +------+-------------+--------+----------+ > > | 35 | Viridiana | W | McCarthy | > > | 47 | Crystal | O | Cassady | > > | 67 | Ricardo | L | Johnson | > > | 183 | Christopher | E | Denver | > > | 237 | Christopher | B | Brenner | > > | 255 | Danielle | W | Nickels | > > | 299 | Christine | D | Dexter | > > | 300 | Rachel | J | Baker | > > | 339 | Jenna | O | Murray | > > +------+-------------+--------+----------+ > > 9 rows in set (0.00 sec) > > > > > > > > -- > > 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]
