MySQLi Update is not working properly

Question

I am trying to update one of my row with PHP using MySQLi and if I refresh PHPMyAdmin less than 1 second after update it's sucessfull but if I only check the data 2 seconds+ after the update it doesn't update.

For exemple:

'UPDATE orders SET MachineID = '.$id.' WHERE OrderID = '.$OrderID.
                   'AND ProductID = '.$ProductID

Does not work unless I refresh quickly but...

'UPDATE orders SET MachineID = 2 WHERE OrderID = 4 AND ProductID = 12'

Will work no matter how long after I refresh. (Those are the data I normaly use to test.)

So I though it would be my variables, but I'm using them almost 10 times before this part of the code in other queries and it works perfectly.

• I tried to trim() the variable and it did not help.
• I also tried to use mysqli_real_escape_string() with no success.
• mysqli_error() is not giving me anything.
• mysqli_affected_rows() is giving me "1" which is what it is suppose to be.
• And the weird part is if I execute 'SELECT MachineID FROM orders WHERE OrderID = 4 AND ProductID = 12', it gives me the updated answer even if phpMyAdmin does not update the data.

There is no other code after this, so nothing that could "reverse" the update.

A normal "test" ouput looks like this:

Edit: This it what the browser outputs.

ID: "2" //$id
OrderID: "4" //$OrderID
ProductID: "12" //$ProductID
UPDATE orders SET MachineID = 2 WHERE OrderID = 4 AND ProductID = 12 //Query
boolean true //Result var_dump
1 //Number of rows affected
2 //Machine ID

Note: The quotes are not part of the variables.

Edit: This is the PHP code

$query = 'UPDATE orders SET MachineID = '.$id.' WHERE OrderID = '.$OrderID.' AND ProductID = '.$ProductID;          
echo 'ID: "'.$id.'"<br/>
     OrderID: "'.$OrderID.'"<br/>
     ProductID: "'.$ProductID.'"<br/>'.$query.'<br/>';

$res = $db->query($query);
var_dump($res);

echo mysqli_affected_rows ($db).'<br/>';   
$result = $db->query('SELECT MachineID FROM orders WHERE OrderID = 4 AND ProductID = 12');      
$result = $result->fetch_array();
echo $result[0];

I really don't understand why it would work in the file and after a quick refresh but not if it takes to long to retreive the data. It's like it would reset after a certain amount of time if it's not fetch.

I've been working on this for almost 2 days now I have no idea why it's not working. This is some pretty simple SQL query.

Edit: I've look into MySQL binary logs and it seems that I'm updating it back to 1 every time. The only way this could be happening is if the file would run twice, but if it runs twice why would the output be there only once ?

Edit: Ok, so it seems like the problem comes from Google Chrome. I've tested it on IE and it works. For some reason Chrome would be running the file twice.

Answer 1

Ok so I was able to find the problem and fix it.

Problem: The problem was the famous "favicon" bug with Chrome which is trying to get the icon even if it doesn't exist, therefore the file is called twice.

Fix: Since this file was meant to be called through an Ajax call the bug is not triggered since Chrome will not try to look for the "favicon". I basicly fixed the bug by testing it how it was supposed to be run and not just testing the file itself.