Return row from subselect

I have this MySQL DB scheme:

users (id, login)
coins (userid, value, curr)

I need to write select which will return result: login and max coin he have and currency of this coin.

I've tryed something like that:

SELECT login, 
(
  SELECT value, curr
  FROM coins 
  WHERE coins.userid = users.id
  ORDER BY value DESC
  LIMIT 1
) AS ROW(value, curr开发者_运维百科)
FROM users

Its not working... I'll recieve error, that "Operand should contain 1 column(s)". I expected it, but I dont know any way, how to make it.

So i guess: Is there any way to return multiple-column-single-line (row) from subquery to parent query?

(Yes, I can use two subqueries, but its not effective.)

Thanks for your time.

SELECT u.login, g.MaxVal, c.curr
FROM users u JOIN coins c ON u.id = c.userid 
  JOIN (
    SELECT userid, MAX(`Value`) MaxVal
    FROM coins
    GROUP BY userid
  ) g ON c.userid = g.userid AND c.Value = g.MaxVal 

In a case of ties, the above query will return all coins with the highest value, if you want to only select 1 of the coins, you can add a GROUP BY to the outer query:

SELECT u.login, g.MaxVal, c.curr
FROM users u JOIN coins c ON u.id = c.userid 
  JOIN (
    SELECT userid, MAX(`Value`) MaxVal
    FROM coins
    GROUP BY userid
  ) g ON c.userid = g.userid AND c.Value = g.MaxVal 
GROUP BY c.userid