Using fetch assoc gets the columns, not the values. If you want to count rows from MySQL, you can simply use mysql_num_rows. Example:
PHP Code:
$query = mysql_query("SELECT * FROM `table` WHERE `blah`='blah' LIMIT 1", $connection);
$rowCount = mysql_num_rows($query);
(unless you were wanting the total count of the columns)
Then you could use
$rowCount = count(mysql_fetch_assoc($res));
The mysql_fetch_assoc doesn't loop through, so your result would always be 1 in your example. It contains an array of colums. So you would have to use this way to count them