Check if value is unique

[Nick_Deboo1]

Hi

We have a software that links contact form on our website and the link contains a ID number. It's easy to store the ID but I would like to check if the ID is unique. We only allow one form submit.

Is is possible to check if the value of a custom field is unique?

ps. I know that an id is not the best solution, a custom solution in the software would be better...

[SanfordWhiteman]

Unique across your entire Marketo database?

Or unique as in the form was not already posted on behalf of this email address with this ID value?

Please explain the use case a bit more.

[Nick_Deboo1]

This is my use case. Notice that the form ID comes from our software in a parameter. Our software generates an unique ID.

October 1st

Person A submits form:   john.doe@example.com     ID= 1234   -> ok

November 1st

Person A submits form:   john.doe@example.com     ID= 1234   -> not ok, we don't want the same person submitting the form again. The person will get an email saying he has done this already.

Person A: john.doe@gmail.com ID=1234    ->not ok because this is the same user as on October first. We know this by ID

Can we in the last submit check if the same ID has been used by another email address?

[Nick_Deboo1]

So far I haven't been able to check if a field (across the entire database), contains the same value.