Is there a way to force unique entries into Excel columns? In Access (or any other database for that matter), if you make a column of a table a primary key, you are prevented from inserting duplicate vaules into a table for that column. Is there anyway to accomplish this in Excel? I have seen ways to generate a list of the unique entries in a column and add them to another column. But I want to prevent the user from inserting a value if it already exists.
