Unique value Index (duplicates are same)

[Anonymous]

How would I create a unique value index with Dax code? I am in the process of creating a ragged heirachy using a Tabular model so it has to be done using DAX code (I can't use PQ, etc). What I am looking for is a column which will assign an index for each instance where the item is distinct. If it is duplicated on another row I want it to be assigned the same index (as shown in the picture).

Thanks

[BeaBF · Accepted solution]

@Anonymous It seems simpler to me like this:

Index Column = RANKX ( Table, Table[Item],, ASC, DENSE )

Try it!

B.

[Anonymous]

Thanks, at first glance this looks to work. I have 57k rows though so I need to make sure that its consistent.

[Greg_Deckler]

@Anonymous Indexes in DAX are not particularly easy and were once thought impossible. Hard to guarantee any sort of sort order, not that I see what sort order you would want. You can try this:

Column = 
  VAR __Item = [Item]
  VAR __Text = CONCATENATEX('Table',[Item],"|")
  VAR __Count = PATHLENGTH(__Text)
  VAR __Table = 
    ADDCOLUMNS(
      GENERATESERIES(1,__Count,1),
      "__Item",PATHITEM(__Text,[Value])
    )
  VAR __TableFinal = 
    SUMMARIZE(__Table,[__Item],"Index",MINX(FILTER(__Table,[__Item]=EARLIER([__Item])),[Value]))
RETURN
  MINX(FILTER(__TableFinal,[__Item] = __Item),[Index])

Original concept is from The Mythical DAX Index: (2) The Mythical DAX Index - Microsoft Power BI Community