Bana en fazla gelen sorulardan birisi...

mySQL:

SELECT column FROM table
ORDER BY RAND()
LIMIT 1

PostgreSQL:

SELECT column FROM table
ORDER BY RANDOM()
LIMIT 1

Microsoft SQL Server:

SELECT TOP 1 column FROM table
ORDER BY NEWID()

IBM DB2:

SELECT column FROM table
ORDER BY RAND()
FETCH FIRST 1 ROWS ONLY

Oracle:

SELECT column FROM
( SELECT column FROM table
ORDER BY dbms_random.value )
WHERE rownum = 1