count(*) VS num_rows

allworknoplay · 04-02-2009, 07:37 PM

Hey guys, I think I read this somewhere else on this forum but I wanted to confirm. Do you all believe that this method is a better way to retrieve the number of rows and is quicker than using the mysql_num_rows function?

Code:

###NUMBER OF USERS(FASTER)
$query = mysql_query("SELECT count(*) as user_count FROM users");
$results = mysql_fetch_assoc($query);
$results[user_count]";


###NUMBER OF USERS(SLOWER)
$query = mysql_query("SELECT user_id FROM users");
$num_results = mysql_num_rows($query);

Also, I remember reading somewhere that if you want the count, you don't need to use the "*" symbol since it will read all columns, so instead just pick one column to get the count.

So would it be even better to use this statement?

Code:

SELECT count(user_id) as user_count FROM users