Validate that there isn't duplicate emails

I have a bit of a unique issue. I want to make sure there is not dublicate entries within my database, the form is for a coupon and I don't want the same emails used more than once to redeem a coupon. However this is not a 'registration' form. There is no username, etc. I have connected the form to a database using the create table setup in chrono backend.

What server side validation can I add to verify that the email is not already in the database? I have seen several situations where this has been done BUT its usually with a registration form and the database its accessing to verify is different.

Any guidance? Ideas?

Thanks in advance

Hi hungree,

Yes you can do that with server-side validation - include the MySQL query to check the database.

You can also do it with AJAX in the form. I think there was a similar query here a few weeks ago.

Bob