Как избавиться от дублей?

$sql = $db->query( "SELECT surname, count(*) FROM dle_users GROUP BY surname" );
while ( $row = $db->get_row( $sql ) ) {
echo $row['surname'].'<br />';
}

$sql = $db->query("SELECT DISTINCT surname FROM dle_users");
while ( $row = $db->get_row( $sql ) ) { 
echo $row['surname'].'<br />'; 
}