error with mysql_fetch_assoc()

[Alexia Moon]

I have downloaded a Wordpress template E commerce theme. One of the features of the template is that I can select a piece of clothing and adjust it's price using the 'add_attributes ' tag. When I do that, it seems to work perfectly until I get to the part where I have to add inventory amount and I get this error message

Warning: mysql_fetch_ass oc(): supplied argument is not a valid MySQL result resource in /homepages/11/xxxxxx/htdocs/xxxxxx/xxxxxx/wordpress/wp-content/themes/xxxxxx/lib/engine/backend_actions .php on line 1712

The lady that created this website is trouble shooting it for me but I also need to find out information for myself too.

Here is the code

function display_attributes_data($meta_value,$order_by_clause){

	$table		= is_dbtable_there('inventory');
	$qStr		= "SELECT * FROM $table WHERE ID_item = '$meta_value' $order_by_clause"; // ORDER BY
	$res 		= mysql_query($qStr);							

	$data		= NULL;

		while($row = mysql_fetch_assoc($res)){
			
				$data .= "<tr>";
				
				foreach($row as $k => $v){
					if($k != 'iid' && $k != 'ID_item' && $k != 'amount' && !empty($v)){
						$data .= "<td>$v</td>";
					}			
				}
				
				$data .= "<td><input type='text' name='$row[iid]' value='$row[amount]' /></td></tr>";
		}

return $data;
}

Can anyone help me please? I am building a baby store and want this up by Feb. I have tons of stock to add on here and it is delaying the process.

[Dormilich]

the reason is simple (because it’s the #1 problem when working with MySQL): your query fails and mysql_query() returns false which in turn is not the right parameter type for mysql_fetch_ass oc().

you must always check the return values of each of your mysql_* functions (or use PDO in Exception mode)

like

$r = mysql_query($sql) or die(mysql_error());

PS. your code is open to SQL Injection.