wangqi <wangqi@xxxxxxxxxxx> writes: > ¡öSQL-3 > select * from wk_mclid1 where id1= (round((random() * (10-1))::integer) > + 1)::integer; > When we excute SQL-3,sometimes the result was 0 record or more than 1 > record. > Why? random() is re-evaluated for each row scanned by the SELECT. If you don't want that, you can use a WITH to lock down the result of a single random() call. regards, tom lane -- Sent via pgsql-admin mailing list (pgsql-admin@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
