How to avoid duplicate string value input in one column?

W

Wavelet

Hi,

I want to set a constraint on one excel column so that when the input
is duplicate
with other column, excel sheet will refuse to accept. It's string
type. Does anyone
know how to implement it in excel 2003?

Thanks,
--Wavelet
 
T

T. Valko

Use data validation

Assume you want to restrict entry into column A if column B already contains
the value

Select column A
Goto the menu Data>Validation
Select Custom
Formula:

=COUNTIF(B:B,A1)=0

OK out

Note that a user can still copy/paste or drag-n-drop a restricted value into
column A.

Biff
 
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