How to validate my form entry with my database?

Hi,

I have made a form in which I want students to enter their Admission no. and DOB, which will be verified by my database. If the entry will match my database, submit button will redirect to my website else, error will appear. 

Please suggest the best possible way for this functionality. 

Unfortunately, you cannot have the field validate from an external database. However, you can use Show/Hide field conditions to check the entered value.

Here's a guide on how the conditions work: Hide-or-Show-Multiple-Fields-at-Once

Here's how it will look like:

Hope that helps. Thank you.