[SittingonDucks]

I have a query set in a string:

$query="UPDATE `all` SET FilterToggle='0' WHERE id=" . $_SESSION['id']; 

When I run mysql_query() it returns false when I call the mysql_num_rows function. However I check it before the _num_rows function:

if ($_POST['filter'] == true) 
	{
		$query="UPDATE `all` SET FilterToggle='0' WHERE id=" . $_SESSION['id']; 
		$res=mysql_query($query) or die(mysql_error()); 
		if ($res) { 
			echo mysql_num_rows($res);
		} 
		else 
		{ 
			echo 'bad query'; 
		} 
	}

So I figured it's either a problem with my logic of the code or the query. It says mysql_num_rows() expects the first argument/parameter to be a resource and not a boolean.

[CTphpnwb]

I'm guessing $_SESSION['id'] isn't set. See what your query looks like after it's built:

echo $query;

or

error_log($query);

[JackOfAllTrades]

Yes, always use this pattern when running a query that you're assembling from user-input data:

$sql = "UPDATE `all` SET FilterToggle='0' WHERE id=" . $_SESSION['id'];
$result = mysql_query($sql);
if (!$result) {
    // If debugging, then die here.
    die("Query {$sql} failed: " . mysql_error());

    // If this is exposed to the outside world, log the error somewhere
    // instead of using it in a die()
}

[SittingonDucks]

		if ($_POST['filter'] == true) 
		{
			$query="UPDATE `all` SET FilterToggle='0' WHERE id='" . $_SESSION['id'] . "'"; 
			echo $query; 
			$res=mysql_query($query); 
			if (!$res) { 
				die("Query {$sql} failed: " . mysql_error()); 
			} 
			else 
			{ 
				echo "<br /> Query $query is fine! [$res]"; 
			} 
		}

Returned:

Quote

UPDATE `all` SET FilterToggle='0' WHERE id='30'
Query UPDATE `all` SET FilterToggle='0' WHERE id='30' is fine! [1]

[Dormilich]

note that SQL INTEGER field values are passed without quotes.

[SittingonDucks]

		if ($_POST['filter'] == true) 
		{
			$query="UPDATE `all` SET FilterToggle=0 WHERE id=" . $_SESSION['id']; 
			echo $query; 
			$res=mysql_query($query); 
			if (!$res) { 
				die("Query {$query} failed: " . mysql_error()); 
			} 
			else 
			{ 
				echo "<br /> Query: <br /> <div style='background-color:#970026; width: 350px; height: 100px; border: solid black 2px;'>{$query}</div> <br /> All is good! {$res}";
				echo mysql_num_rows($res); 
			} 
		}

Quote

UPDATE `all` SET FilterToggle=0 WHERE id=30
Query:
UPDATE `all` SET FilterToggle=0 WHERE id=30

All is good! 1
( ! ) Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in C:\wamp\www\___________\filterc.php on line 27

This post has been edited by SittingonDucks: 07 February 2012 - 09:46 AM

[SittingonDucks]

It seems to return true, but it doesn't give a resource...

[SittingonDucks]

Got it working. Nevermind ;]

[JackOfAllTrades]

The reason, which you may already know but I'll add it here for posterity, is mysql_num_rows only works with SELECT statements, i.e., those queries that return rows of data. For other queries, i.e. those where you're changing data already within the database, the proper call is mysql_affected_rows. This info is available in the excellent documentation:

Quote

Use mysql_num_rows() to find out how many rows were returned for a SELECT statement or mysql_affected_rows() to find out how many rows were affected by a DELETE, INSERT, REPLACE, or UPDATE statement.