Adobe Acrobat PDF forms can be extended with PHP, SQL, and cURL to enable real time interactions with SQL databases and REST APIs.
An extended Acrobat form can be used as a programmable runtime, to design, configure, test, and share as data-based process interfaces.

If you'd like to test, click here to download a copy of the form shown in the screenshot below and open with Acrobat Reader or Acrobat Pro.