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 ''marlat' USING latin1) COLLATE latin1_swedish_ci' at line 1
Perche' usi la conversione del charset??? lascialo fare a phpmyadmin ....

codice:
$query = "SELECT * FROM `giocatori` WHERE ";

if($nome !=  "") { $query = "$query `nome` LIKE '$nome' "; }