Formula that recognizes duplicates
 

I need a formula that tells me if there is a duplicate within the same
column. I have no idea how to go about this. I am wanting to enter in
Product ID numbers and if there is a duplciate I need to be warned. I would
appreciate any help anyone can give - Thanks!

Check out this web site of Chip Pearson's.

Scroll down to the "D's", and see all the pages pertaining to duplicates.

http://www.cpearson.com/excel/topic.htm
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HTH,

RD
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Please keep all correspondence within the Group, so all may benefit!
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"Courtneyf04" wrote in message
...
I need a formula that tells me if there is a duplicate within the same
column. I have no idea how to go about this. I am wanting to enter in
Product ID numbers and if there is a duplciate I need to be warned. I
would
appreciate any help anyone can give - Thanks!

Take a look he

http://cpearson.com/excel/duplicat.htm

and

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


In article ,
"Courtneyf04" wrote:

I need a formula that tells me if there is a duplicate within the same
column. I have no idea how to go about this. I am wanting to enter in
Product ID numbers and if there is a duplciate I need to be warned. I would
appreciate any help anyone can give - Thanks!

This solution does not allow me to check for existing numbers. Lets say that
I have a list of numbers but change a number somewhere near the top. Data
Validation does not check that number.

"JE McGimpsey" wrote:

Take a look he

http://cpearson.com/excel/duplicat.htm

and

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


In article ,
"Courtneyf04" wrote:

I need a formula that tells me if there is a duplicate within the same
column. I have no idea how to go about this. I am wanting to enter in
Product ID numbers and if there is a duplciate I need to be warned. I would
appreciate any help anyone can give - Thanks!

Which of the many solutions on those two web pages are you talking about?

If the one at http://cpearson.com/excel/NoDupEntry.htm, did you use
absolute references for your input range?

E.g.,

=COUNTIF($A$1:$A$50,A1)=1

not

=COUNTIF(A1:A50,A1)=1

????

Select column A, inputIn article
,
"Courtneyf04" wrote:

This solution does not allow me to check for existing numbers. Lets say that
I have a list of numbers but change a number somewhere near the top. Data
Validation does not check that number.

the no dupentry does not work on numbers that are already entered. It only
checks against the numbers that are pre-existing. I want to have a list and
without entering any more numbers check to see if there are duplicates in the
exising list. I hope that makes sense.

"JE McGimpsey" wrote:

Which of the many solutions on those two web pages are you talking about?

If the one at http://cpearson.com/excel/NoDupEntry.htm, did you use
absolute references for your input range?

E.g.,

=COUNTIF($A$1:$A$50,A1)=1

not

=COUNTIF(A1:A50,A1)=1

????

Select column A, inputIn article
,
"Courtneyf04" wrote:

This solution does not allow me to check for existing numbers. Lets say that
I have a list of numbers but change a number somewhere near the top. Data
Validation does not check that number.

That's what several of the formulae in the first reference I listed does
- it checks to see if there are duplicates in the existing list. Look
under "Testing For Duplicate Entries"

In article ,
"Courtneyf04" wrote:

the no dupentry does not work on numbers that are already entered. It only
checks against the numbers that are pre-existing. I want to have a list and
without entering any more numbers check to see if there are duplicates in the
exising list. I hope that makes sense.

Thank you very much!

"JE McGimpsey" wrote:

That's what several of the formulae in the first reference I listed does
- it checks to see if there are duplicates in the existing list. Look
under "Testing For Duplicate Entries"

In article ,
"Courtneyf04" wrote:

the no dupentry does not work on numbers that are already entered. It only
checks against the numbers that are pre-existing. I want to have a list and
without entering any more numbers check to see if there are duplicates in the
exising list. I hope that makes sense.