Any Way of Creating a 'Unique Key'?

[hustla7]

I'm making a mortgage lending database system for my GCSE ICT coursewor
and I have a field in the database called ID Number...is there any wa
of making it a unique field i.e. no two values can be the same- an
sort of validation or anything?

THAN

 

[Franz Verga]

I'm making a mortgage lending database system for my GCSE ICT
coursework and I have a field in the database called ID Number...is
there any way of making it a unique field i.e. no two values can be
the same- any sort of validation or anything?

THANX

Hi,

First of all select the column, I assume is the A column, then from menu
Data, Validation, tab Settings, choose Custom under Allow and input this
formula:

=COUNTIF(A:A,A1)=1


--
(I'm not sure of names of menus, options and commands, because
translating from the Italian version of Excel...)

Hope I helped you.

Thanks in advance for your feedback.

Ciao

Franz Verga from Italy

 

[hustla7]

I cant find the tab settings thingy...:S

thankyo

 

[davesexcel]

Highlight the range say A:A if it is in column A
goto data, validation,custom
enter this formula in the box
=COUNTIF(A:A,A1)<2
then go to the error alert tab and enter the message you want, when
duplicate number is entered


here's a little clip on data Validation

http://www.datapigtechnologies.com/flashfiles/datavalidation.htm

 

[hustla7]

Thanks a lot for all of your help- both methods do work!! Thank you onc
again

 

[SteveW]

Data, Validation
Its the first tab.

Steve

I cant find the tab settings thingy...:S

thankyou

 

[Gord Dibben]

Yes, you can use Data Validation.

Chip Pearson's site shows how.

Note the caveats.

http://www.cpearson.com/excel/NoDupEntry.htm


Gord Dibben MS Excel MVP