Fire event once form submitted and query db7 database

Hi,

When our form is submitted, all details are successfully added to database. I notice that there is a unique form_id for each record. I have a program (create-pdf.php) that gets the record from the database using the form_id and creates a pdf to send to the user (prefilled with user data form the database).

However, I cannot find a way on form submission of retrieving the form_id (other than taking the last entry in the database, which will not necessarily be accurate).

Is there any way of returning the form_id on form submission, or somehow sending the form_id to create-pdf.php so the pdf gets generated?

Thanks