How to prevent repeat donation from same email

Hello.

I need to prevent repeat donation from same email.

My site is a new concept.
It combines some features of Donation site with some features of Membership site.

It is built with Joom Donation extension.

It does not create user accounts.

I need php customization. I need email validation subroutine to prevent repeat donation from same email.

I need to red-flag and halt Donation Form-Continue when Donation email = email already in jd_donors database table.

This is similar to 'prevent same username', or to 'prevent same email address' in Membership Pro.

Options:
1 - I pay you for custom work on JD, or...
2 - You tell me which file(s) to modify, & I pay someone else for custom work, or...
3 - You don't help.

I hope you can help!

In the table _jd_donors, I already set the email column to Unique.

Now when i submit a test transaction with same email,
the site breaks and I get a browser error #1602 - Duplicate entry 'bill@testmail.com' for key 'email'.

I need a email validation routine to red-flag duplicate email address when user clicks Continue on Donation Form. I probably also need a bot-check on Donation Form to prevent Denial of Service attack.

Hope you can help!!

I have already asked how to hire your team for custom work in an earlier post.

You didn't reply!!!

At least give a reply!

I bought your extension. I need to customize it. What do I gotta do?

Thx.

Dave

Hi Dave,
With custom work request, please submit new ticket on category: Joom Donation in Ticket system. We will answer you sooner.
Thanks
Dam