?
Solved

mysql_num_rows() error...

Posted on 2011-03-25
5
Medium Priority
?
450 Views
Last Modified: 2012-06-27
I'm trying to return a number of records in a table using mysql_num_rows();

I'm having issues however, I get the following message:

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in d:\....

For the sake of learning PHP i simply copied this code from a tutorial and plugged my info in, thinking I'd get it to work and disect it.  No such luck.

I've been able to run insert statements, but for some reason the mysql_num_rows() isn't working.  The code I use is posted below.

Any ideas?  THANKS!
<?php
$dbhost = 'my.remote.mysqlserver';
$dbuser = 'myusername';
$dbpass = 'mypassword';
$dbname = 'mydatabase';


$link = mysql_connect($dbhost, $dbuser, $dbpass);
mysql_select_db($dbname, $link);

$result = mysql_query("SELECT * FROM myTable", $link);
$num_rows = mysql_num_rows($result);

echo "$num_rows Rows\n";

?>

Open in new window

0
Comment
Question by:slightlyoff
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
5 Comments
 
LVL 8

Expert Comment

by:Rik-Legger
ID: 35217789
Did you also test it with the database configuration (host, user, pass, name) like above?
Because you should have a existing database to connect to before this can work.
0
 
LVL 1

Author Comment

by:slightlyoff
ID: 35217910
i was able to do an insert using the configuration above... is that what you mean?
0
 
LVL 8

Accepted Solution

by:
Rik-Legger earned 1000 total points
ID: 35217985
Try this,
this should give you some helpfull error messages when they are thrown.

<?php
$dbhost = 'my.remote.mysqlserver';
$dbuser = 'myusername';
$dbpass = 'mypassword';
$dbname = 'mydatabase';


$link = mysql_connect($dbhost, $dbuser, $dbpass);
if (!$link) {
    die('Could not connect: ' . mysql_error());
}
mysql_select_db($dbname, $link);

$result = mysql_query("SELECT * FROM myTable", $link);
if (!$result) {
    die('Invalid query: ' . mysql_error());
}
$num_rows = mysql_num_rows($result);

echo "$num_rows Rows\n";

?>

Open in new window

0
 
LVL 5

Assisted Solution

by:tsmgeek
tsmgeek earned 1000 total points
ID: 35217990
put some error catching in your code to look if the problem is the db connection

<?php
$dbhost = 'my.remote.mysqlserver';
$dbuser = 'myusername';
$dbpass = 'mypassword';
$dbname = 'mydatabase';


$link = mysql_connect($dbhost, $dbuser, $dbpass);

if (!$link) {
    die('Not connected : ' . mysql_error());
}

// make foo the current db
$db_selected = mysql_select_db($dbname, $link);
if (!$db_selected) {
    die ('Can\'t use foo : ' . mysql_error());
}


$result = mysql_query("SELECT * FROM myTable", $link);
$num_rows = mysql_num_rows($result);

echo "$num_rows Rows\n";

?>

Open in new window

0
 
LVL 1

Author Closing Comment

by:slightlyoff
ID: 35218144
I'm a moron...  thanks for your help!  I was able to track down the problem... the table had been renamed, after I had tested the insert statments...

Thanks for the example code!
0

Featured Post

Secure Your WordPress Site: 5 Essential Approaches

WordPress is the web's most popular CMS, but its dominance also makes it a target for attackers. Our eBook will show you how to:

Prevent costly exploits of core and plugin vulnerabilities
Repel automated attacks
Lock down your dashboard, secure your code, and protect your users

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This post contains step-by-step instructions for setting up alerting in Percona Monitoring and Management (PMM) using Grafana.
In this series, we will discuss common questions received as a database Solutions Engineer at Percona. In this role, we speak with a wide array of MySQL and MongoDB users responsible for both extremely large and complex environments to smaller singl…
The viewer will learn how to create a basic form using some HTML5 and PHP for later processing. Set up your basic HTML file. Open your form tag and set the method and action attributes.: (CODE) Set up your first few inputs one for the name and …
In this video, Percona Solution Engineer Dimitri Vanoverbeke discusses why you want to use at least three nodes in a database cluster. To discuss how Percona Consulting can help with your design and architecture needs for your database and infras…
Suggested Courses

765 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question