Mine

function update_stats ( $user_id, $stats_array )
{
	global $db;

	$_i = count($stats_array);
	$i = 1;

	$sql .= "UPDATE beta_users_stats SET ";

	foreach($stats_array as $stat => $value )
	{
		$sql .= $stat . ' = ' . $stat . ' ' . $value;
		$sql .= ($i < $_i) ? ', ' : ' ';
		$i++;
	}

	$sql .= "WHERE user_id = '" . $user_id . "'";
	if ( !($db->sql_query($sql)) ) { message_die(GAME_ERROR, 'ERROR: Unable to update statistics.'); }
}