2

I have an excel spreadsheet - is it possible to have validation so that a column cannot contain a value that already exists in the column?

  • @DaveParillo - aiming for the Taxonomist badge, are you ? :)) – Rook Oct 21 '09 at 20:22
5

Yes, from this example ...

  1. Select a range of cells, for example, A2:A20.
  2. Select Data -> Data Validation (in Data Tools Group).
  3. In Data Validation dialog box, select Settings -> Allow -> Custom.
  4. In the Formula box, enter the following formula: =COUNTIF($A$2:$A$20,A2)=1
  5. Select the Error Alert tab.
  6. In the Title box, enter: Duplicate Entry.
  7. In the Error message box, enter: The value you entered already appears in the list above.
  8. Click OK.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.