Group By value RAND()

Question

It's possible get a random value of the group by?

----------------
 nID |  val
---------------
  A  |   XXX
  A  |   YYY
  B  |   L
  B  |   M
  B  |   N
  B  |   P
----------------

With this SQL:

SELECT nID, VAL FROM T1 GROUP BY nID

My result always is:

nID  val
--------
A    XXX
B    L

But i want a diferent result of evey nID. Like:

nID  val
--------
A    YYY
B    N

or

nID  val
--------
A    XXX
B    P

It's possible?

http://sqlfiddle.com/#!2/357b8/3

Answer 1

Use a sub-query.

SELECT r.nID,
(SELECT r1.val FROM T1 r1 WHERE r.nID=r1.nID ORDER BY rand() LIMIT 1) AS 'val' FROM T1 r 
GROUP BY r.nID

http://sqlfiddle.com/#!2/357b8/18

Answer 2

You can use order by rand() then group by them.

Like

  SELECT nID, VAL FROM (
  SELECT nID, VAL
  FROM T1
  ORDER BY RAND()
  )AS subquery
GROUP BY nID