Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resourc

[twiggs462]

A client of mine is having an issue with an admin area of their site that I never encountered before...

 

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

 

The code that is being referenced is:

 

// new sql to pull associated products for seleceted family

$restwoway = mysql_query("SELECT * FROM members order by name;");
$numrows=mysql_num_rows(restwoway);

if($numrows=0){
echo "Invalid entry";
}
else { ?>

 

Anyone see any errors here or... do you need me to provide additional details. I never seen this error before and not sure how to address it  . Thank you for any ideas you might have.

[Pikachu2000]

The query is failing. Echoing mysql_error should give you some insight as to why.

[twiggs462]

Ok. I just added this:

 

$restwoway = mysql_query($sql);
if (!$restwoway) {
die("I JUST GOT A QUERY ERROR!!!<br />Query is: $sql<br />Error is: ".mysql_error());
}

 

And it resulted in this:

 

I JUST GOT A QUERY ERROR!!!

Query is:

Error is: Query was empty

[Jessica]

And....

Do you see a problem there?

[jazzman1]

Php is not like C++.

$numrows=mysql_num_rows(restwoway);

[twiggs462]

changed this:

 

$numrows=mysql_num_rows(restwoway);

 

to this:

 

$numrows=mysql_num_rows($restwoway);

 

Seems to have fixed it... I feel... well... ridiculous... thanks for the help in steering me.

[Pikachu2000]

Actually in this case, in your original code, look at the value you've passed to mysql_num_rows(). Is it missing something?

[Jessica]

Also, the if() statement will ALWAYS return true.

[twiggs462]

Actually in this case, in your original code, look at the value you've passed to mysql_num_rows(). Is it missing something?

 

Not sure... I will need to look further.

[twiggs462]

Also, the if() statement will ALWAYS return true.

 

Does this mean that this is somehow just generally incorrect?

 

// new sql to pull associated products for seleceted family

$restwoway = mysql_query("SELECT * FROM members order by name;");
$numrows=mysql_num_rows($restwoway);

if($numrows=0){
echo "Invalid entry";
}
else { ?>

 

Sorry I am new to this and need to brush up... new more about PHP years back... had to learn ASP for work and now feel rusty 

[Jessica]

In the if(), you're assigning, not comparing. So it will always evaluate to true.

[twiggs462]

I don't remember how to compare or what it should be compared to...

[Pikachu2000]

Actually in this case, in your original code, look at the value you've passed to mysql_num_rows(). Is it missing something?

 

Not sure... I will need to look further.

 

What are variables supposed to start with?

 

I don't remember how to compare or what it should be compared to...

 

Assignment operators

Comparison operators

[Jessica]

http://php.net/docs.php

[jcbones]

= assign

== compare

=== strict compare