Unique Validation on Calculated Column

Question

I have 2 columns (first name and last name) in a SharePoint custom list. I have a calculated column called "full name" just concatenates the first and last name columns.

Due to requirements, I need to be able to store the first and last names in separate columns which is why I used a calculated field for the full name so that users don't need to enter the full name a second time.

However, I need to be able to verify that a "full name" is unique to the list. Is there a way to apply a uniqueness validator on a calculated column? If not, are there any possible solutions to verify the uniqueness of a full name?

Answer 1

As per my understanding there are two solutions to this

1. Using client side scripting

In this case you should edit the new/edit form and add JavaScript which goes and check if FirstName + ' ' + LastName already exists in the list. For that you can use SPServices and then handle this validation on PreSaveAction method.

This approach will provide a good user experience.

2. Using Event Receivers

This approach require deployment into the farm. You should handle ItemAdding event and then cancel the insert in case of duplicates.