Với MySQL:

SELECT column FROM table
ORDER BY RAND()
LIMIT 1

Với PostgreSQL:

SELECT column FROM table
ORDER BY RANDOM()
LIMIT 1

Với Microsoft SQL Server:

SELECT TOP 1 column FROM table
ORDER BY NEWID()

Với IBM DB2

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

Với Oracle:

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