MySql rows count

There are two ways that i used to view the MySql number of rows.

The first method is to use the php function: mysql_num_rows()

$rows = mysql_num_rows(mysql_query('SELECT id FROM accounts'));
echo $rows;

The second method is to use the mysql function: count() which is faster

$rows = mysql_fetch_row(mysql_query('SELECT count(id) FROM accounts'));
echo $rows[0];