PHP: MySQL query duplicating update for no reason

Question

The code below is first the client code, then the class file.

For some reason the \'deductTokens()\' method is calling twice, thus charging an account double. I\'ve been

Answer 1

I know this will sound strange but make sure that you don't have tag with empty src="" attribute or any css style refering to empty url (like background: url();) on your site around the place when you have your code that runs twice.

Read about some trouble this may cause here: http://hi.baidu.com/zhenyk/blog/item/38a1051fc63b96c3a686698f.html

Answer 2

Another long shot, but it happened to me once in Firefox - doubled page executions, resulting in doubled inserts and updates - close your browser and restart.

Answer 3

The line:

header('location: account.php');

Forwards the browser, but doesn't end the php script.
This might be fine, the code-snippet you gave doens't "do" anything after this line.

Another option might be a double-click
If you double-click on the submit button, the form will be sent twice.
We used some javascript to disable the submit button after the first click.