can I query a database table from a jotform?

I am not sure if I fully understand your question, but if you intend to connect your form to a MySQL database using PHP. You need to have knowledge in PHP programming for that. Please check this guide: How to send Submissions to your MySQL Database using PHP

You might also want to check JotForm Webhooks. Please check this blog post: Send-Instant-Submission-Notifications-with-Webhooks. You can find Webhooks example on this guide: Webhook-PHP-Script-Examples

Feel free to get back to us anytime you have questions or in need of further assistance.