mi spiegate il perchè se faccio questo:

Codice PHP:
$sql="SELECT DISTINCT Brand FROM magazine WHERE Category='$category' ORDER BY BRAND ASC";
$QueryBrand=mysql_query($sql) or die (mysql_error()); 
mi da questo errore:
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'SELECT DISTINCT Brand FROM magazine WHERE Category='Riscaldamento' ORDER BY BRAN' at line 1

mentre se faccio così:
Codice PHP:
$QueryBrand=mysql_query("SELECT DISTINCT Brand FROM magazine WHERE Category='$category' ORDER BY BRAND ASC") or die (mysql_error()); 
funziona tutto?