How to set a validation rule for no duplication of car number plate. Help me please.

[FelixHeah]

Hi all!

I've been spending few hours trying to figure out how to set a validation rules for no duplication of a car number plates. The table name is "cabs", I've set the "CabsID" as the primary key and i need a validation rule that restrict the data to be enter if it is already there (Indexed - No Duplicates). Can someone help me?

Felix.

 

[Becky]

Hello and welcome to the forums!

Is that data that you do not want duplicated in one column? You could maybe use a countif function in the 'custom' settings of the data validation options. Assuming that your first cell in the range is A2 you could use the following:

=COUNTIF($A$2:$A$100,A2)=1

where $A$2:$A$100 is the range you have selected for the validation.

If you type in a value that has already been included previously, it should bring up an error.

Hope this helps!

 

[FelixHeah]

Hey Becky! Thx! In my case, i want the whole field to be set as no duplication. Eg; the car number plate that I've entered are not allowed to be enter again. Is the column thingy works like Microsoft excel? Where the first row first column is A1, first row second column is B1?