Chs говоришь одно, ThE0ReTiC - другое, и кто-же прав?
вот что нашёл в мане о сабселект:
``Find number, dealer, and price of the most expensive article.\'\' 
In ANSI SQL this is easily done with a subquery: 
SELECT article, dealer, price
FROM   shop
WHERE  price=(SELECT MAX(price) FROM shop)
In MySQL (which does not yet have subselects), just do it in two steps: 
Get the maximum price value from the table with a SELECT statement. 
Using this value compile the actual query: 
SELECT article, dealer, price
FROM   shop
WHERE  price=19.95
Chs может приведёшь пример?