I have tried rand(), and my sql is: SELECT table.field, rand() AS r FROM tablename WHERE condition ORDER BY r LIMIT 10; However, in the entire select process, I get the same rand() value, it seems that in the entire process, rand() is only executed once. If I use: SELECT tablename.field, rand() FROM tablename WHERE condition LIMIT 10; I can get different rand() value, but I cannot reference the rand() field.
Finally I use this, it seems OK now: SELECT * FROM (SELECT tablename.field, rand() FROM tablename WHERE condition) AS t(table.field, r) ORDER BY r LIMIT 10;
lonefs 2007-08-31
发件人： Niels Nes 发送时间： 2007-08-31 00:55:37 收件人： Communication channel for MonetDB users 抄送： 主题： Re: [MonetDB-users] How to select random resords from MonetDB
On Thu, Aug 30, 2007 at 03:14:39PM +0800, lonefs wrote:
How to select random resords from MonetDB?
Using the RAND() /SRAND() functions you could create random numbers. Depending on your schema you may select random records.
Niels
Thanks!
_________________________________________________________lonefs
2007-08-30
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