On duplicate sql problem

[geroido]

Hi

I have a continuous problem with database insertion. I wonder if you have any advice.

For example, if I allow a user to fill out a booking form and then insert the record in the database it all works well.

I then send the user a message after insert (all happening on the same page) thanking them for their booking. Now the problem I have is if the user right clicks on the webpage and refreshes, it inserts the record again. I don't want this. Is their a way to prevent this.

 

 

[revraz]

Check to see if they exist before inserting

[geroido]

I'm not sure how to do that. Once the record is inserted, the booking number is an auto increment. How would I know what the booking number is so that I can check it. This happens in the database unseen to me.

[BlueSkyIS]

i typically use a session variable to indicate that the visitor has completed an action and that action should not be re-inserted unless the visitor starts over from the beginning. if the session var is 'completed' and the user attempts a refresh, i redirect them to the start page.

[revraz]

Well one thing that would help is redirect them away after they submit to a different thank you page.

[BlueSkyIS]

that would prevent a certain percentage of re-inserts, but not all of them. using sessions will stop all of them.

[geroido]

Thanks all

I'll test out those suggestions now

[BlueSkyIS]

you may also want to use some code to try to prevent browser caching of the form page, though i haven't had to use it since i started using sessions as described above.

 

// Try to prevent caching
header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
header("Cache-Control: no-store, no-cache, must-revalidate");
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");