Error message that includes: mysql_num_rows():

Hello,

I have received the following error message on my website:

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /home/ptremail/public_html/admin/newmail.php on line 431

listed below is an excerpt from that file it is lines 429 to line 439:

 <?
	$sql=mysql_query("SELECT * FROM reads ORDER BY fnum");
	$rows=mysql_num_rows($sql);
	for($i=0;$i<$rows;$i++)
	{
	mysql_data_seek($sql,$i);
	$arr=mysql_fetch_array($sql);
	extract($arr);
	$sq=mysql_query("SELECT * FROM signtask WHERE tasknum=$fnum");
	$signups=mysql_num_rows($sq);
	echo"

PHP:

Any help would be most appreciated. Thanks!

 

Hi, the error tells you your SQL query is somehow wrong - "SELECT * FROM reads ORDER BY fnum" - so first of all do you have table 'reads' and column 'fnum'??

 

Yes, I checked for that and I do have a table 'reads' and a column 'fnum'. I also checked the database connectivity and it is working.

 

Use mysql_error() to know the exact error.

 

OK, When I did that I got the following:

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /home/ptremail/public_html/admin/newmail.php on line 431

Warning: mysql_data_seek(): supplied argument is not a valid MySQL result resource in /home/ptremail/public_html/admin/newmail.php on line 435

Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /home/ptremail/public_html/admin/newmail.php on line 436

Warning: extract() [function.extract]: First argument should be an array in /home/ptremail/public_html/admin/newmail.php on line 437

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /home/ptremail/public_html/admin/newmail.php on line 439

 

You didn't get what I want to say. Use mysql_error() in this manner

$sql=mysql_query("SELECT * FROM reads ORDER BY fnum") or die(mysql_error());

Code (markup):

 

i don't have mysql or php environment immediately with me.
but as the ocde looks so simple, i would like to look at two things.

1. Is there data in the table?

2. remove the order by clause and try.

 

Ok, when I did that I got the following:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'reads ORDER BY fnum' at line 1

 

1. Is there data in the table?

Yes, there is data in the table

2. remove the order by clause and try.

Did this and I still get the same error.

 

?php
$con = mysql_connect("localhost", "peter", "abc123");
if (!$con)
{
die('Could not connect: ' . mysql_error());
}$db_selected = mysql_select_db("test_db",$con);$sql = "SELECT * FROM reads";
$result = mysql_query($sql,$con);
echo mysql_num_rows($result);mysql_close($con);
?>

 

i may be wrong, but i see mysql_query call needs 2 parameters.
in your code the second parameter is missing

 

reads is a reserved word. You need to use backticks around reads e.g.

$sql=mysql_query("SELECT * FROM `reads` ORDER BY fnum") or die(mysql_error());

Code (markup):

 

That was it! Thanks so much! Reps awarded!

 

You are Welcome!