Calculated Column that matches current cloumn only

[alawode]

Hi Experts,

I have a Current  "Customer 1" column with customer names and i am trying to create a new calculated column "Customer 2" that will ONLY accept values that currently exist in Customer 1 and no other values. How do i write a calculation without having to include all the hundreds of names in the Current "customer 1" column in the expression?

Thanks in advance

[Greg_Deckler]

@alawode Not really enough information to go on. You could create a table VAR using DISTINCT to include all of the current values in Customer 1 column and then use the IN operator to check if the calculation is included in that set. Beyond that, not enough information to be specific with regards to a solution. 

Sorry, having trouble following, can you post sample data as text and expected output?
Not really enough information to go on, please first check if your issue is a common issue listed here: https://community.powerbi.com/t5/Community-Blog/Before-You-Post-Read-This/ba-p/1116882

Also, please see this post regarding How to Get Your Question Answered Quickly: https://community.powerbi.com/t5/Community-Blog/How-to-Get-Your-Question-Answered-Quickly/ba-p/38490

The most important parts are:
1. Sample data as text, use the table tool in the editing bar
2. Expected output from sample data
3. Explanation in words of how to get from 1. to 2.

[alawode]

Hi Greg, here's the Sample data attached. Im trying to make sure that "Customer 2" column only has the values in "customer 1" column at all times, and the values should not be duplicated  (should be distinct in "Column 2" even if it appears more than once  in "Column 1").

Thanks

[Greg_Deckler]

@alawode I'm not quite following the use case for this, perhaps you just need to create a new table using the formula: DISTINCT('Table'[Column 1])

[alawode]

@Greg_DecklerHi GReg sorry for th confusion, im simply try to create a column (not a whole table), from the old one (Customer 1), with only the unique values, and not the duplicates

[Greg_Deckler · Accepted solution]

@alawode Well, honestly, that makes no sense to me in terms of practical use. But, be that as it may, you would need an Index column or something that identifies "earlier" and "later" like a date field. Let's say you add an Index column to your table in Power Query Editor, then you could do this:

Customer 2 Column = 
  VAR __Index = [Index]
  VAR __Customer = [Customer 1]
  VAR __MinIndex = MINX(FILTER('Table',[Customer]=__Customer),[Index])
RETURN
  IF(__Index = __MinIndex,[Customer 1],BLANK())

[alawode]

@Greg_DecklerThanks a lot, this works