Display the total registered users

Question

I am trying to show on my page the total Registered Users. I am using this:

<?php
//connect to db
require_once('connect.php');

$usrcnt = mysql_query("SELECT COUNT(DISTINCT ID) FROM members");
$res = mysql_num_rows($usrcnt);

$cnt_mbrs = mysql_fetch_array($res);
?>

And then I call $cnt_mbrs in my page but I get errors like:

mysql_num_rows(): supplied argument is not a valid MySQL result resource...

Is it correct what I am doing?

You do not need to add DISTINCT if ID is a primary key. – usef_ksa Aug 28 '11 at 16:51 — usef_ksa, Aug 28 '11 at 16:51

genesis · Accepted Answer · 2011-08-28T17:17:18.527

3

$usrcnt = mysql_query("SELECT COUNT(*) as cnt FROM members");
$res = mysql_fetch_array($usrcnt);
$cnt_mbrs = $res ['cnt']

Is more correct.

edited Aug 28 '11 at 17:17

answered Aug 28 '11 at 16:44

genesis

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I changed the alias & reference to make it more obvious what is being referred to. – OMG Ponies Aug 28 '11 at 16:47
@Crack So COUNT(*) is faster than COUNT(1) or is it same? – genesis Aug 28 '11 at 16:49
@Crack Thanks. I'll use * in that case :) – genesis Aug 28 '11 at 17:17

score 0 · Answer 2 · answered Aug 28 '11 at 16:46

0

mysql_num_rows returns the number of rows in the result set. Change to

$cnt_mbrs = mysql_fetch_array($usercnt);

answered Aug 28 '11 at 16:46

Ken Keenan

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score -1 · Answer 3 · answered Aug 28 '11 at 16:48

-1

Perhaps for performance considerations it might be better to just keep a running total.

Yes I know that the database will not be normalised

answered Aug 28 '11 at 16:48

Ed Heal

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I was just thinking that the adopted method is not right as each page that requires the number of registered users will have to do a count. Not sure of the indexes etc involved. Just appears to be over-enginnered IMHO. – Ed Heal Aug 28 '11 at 16:57

Display the total registered users

3 Answers3