[Webinar] Streamline your web hosting managementRegister Today

x
?
Solved

mysql_num_rows() error...

Posted on 2011-03-25
5
Medium Priority
?
458 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
  • 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

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

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

This article shows the steps required to install WordPress on Azure. Web Apps, Mobile Apps, API Apps, or Functions, in Azure all these run in an App Service plan. WordPress is no exception and requires an App Service Plan and Database to install
In this blog post, we’ll look at how using thread_statistics can cause high memory usage.
The viewer will learn how to dynamically set the form action using jQuery.
In this video, Percona Solution Engineer Rick Golba discuss how (and why) you implement high availability in a database environment. To discuss how Percona Consulting can help with your design and architecture needs for your database and infrastr…
Suggested Courses

640 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