Problem with ORDER BY and random() ?
От | Jean-Francois.Doyon@CCRS.NRCan.gc.ca |
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Тема | Problem with ORDER BY and random() ? |
Дата | |
Msg-id | 7CDD7B94357FD5119E800002A537C46E2309E3@s5-ccr-r1.ccrs.nrcan.gc.ca обсуждение исходный текст |
Ответы |
Re: Problem with ORDER BY and random() ?
Re: Problem with ORDER BY and random() ? Re: Problem with ORDER BY and random() ? Re: Problem with ORDER BY and random() ? Re: Problem with ORDER BY and random() ? Re: Problem with ORDER BY and random() ? |
Список | pgsql-general |
Hello, I'm trying to retrieve a limited number of random rows, and order them by a column, and am not having any luck with that last part: SELECT * FROM tablename ORDER BY random(), id LIMIT 10 Returns everything more or less as expected, except for the fact that the results aren't sorted by "id" ... I also tried: SELECT random() as sorter, * FROM tablename ORDER BY sorter, id LIMIT 10 But that didn't change anything either. I tried sorting on a column other than "id", but that didn't work any better :( I also tried this on 7.2.1 and 7.3.1 (Both on RH 7.3), thinking this might've been a bug. A quick read of the docs suggests sorting on multiple columns is perfectly legal, as it is used as an example. atlas=# select id from quiz_questions_english order by random(), id limit 10; id ----- 445 756 393 809 335 682 776 754 379 739 (10 rows) atlas=# select random() as sorter, id from quiz_questions_english order by sorter, id limit 10; sorter | id ----------------------+----- 0.000757388770932978 | 455 0.00806515943634564 | 440 0.00836807396652553 | 386 0.00977775268711976 | 323 0.0104504898239162 | 370 0.0166072882789221 | 778 0.0202831137088514 | 416 0.0306016304672703 | 762 0.0340994806187691 | 772 0.0384632679812905 | 371 (10 rows) Anybody know what's going on here ? I've tried this from Zope/psycopg, pgAdminII, and psql ... removing the limit doesn't do any good, and neither does using ASC or DESC ! Any help would be greatly appreciated !! Thanks in advance, Jean-François Doyon Internet Service Development and Systems Support GeoAccess Division Canadian Center for Remote Sensing Natural Resources Canada http://atlas.gc.ca Phone: (613) 992-4902 Fax: (613) 947-2410
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