measure to calculate highest value from grouped total

[67nmark]

Hello,

I have a dataset with a column called CityID and a measure called % of total sales MEASURE. The visual looks like this:

I'm trying to create two measures (and having zero success) showing the top selling city (1) and top percentage (29%).

Very grateful to anyone who can help with this?

Cheers,

Mark

[OwenAuger · Accepted solution]

Hi Mark,

You can use measures like this:

Top Selling City =
FIRSTNONBLANK (
    TOPN (
        1,
        VALUES ( YourTable[CityID] ),
        [% of total sales MEASURE]
    ),
    1
)

Top Percentage =
MAXX (
    VALUES ( YourTable[CityID] ),
    [% of total sales MEASURE]
)

(see this article for the first measure)

The above measures are subject to any filters on CityID. You could replace VALUES with ALL or ALLSELECTED in order to give a sensible result within a visual that includes the CityID dimension.

Regards,

Owen

[67nmark]

Hey Owen,

Thanks so much, that's exactly what I needed.

Cheers,

Mark

[Matty]

Hi Owen,

Hope you're doing OK. 

A couple of questions regarding the solution offered:

• Why have you used FIRSTNONBLANK in the first measure?  What does this account for?
• What happens if two cities share the exact same percentage?  Will both be shown?  And what if we only wanted to show the first city, sorted ascending based on CityID?

Apologies for butting in on the thread - I'm trying to build up my knowledge of DAX, hence the questions...

Cheers,

Matty

[OwenAuger]

Hi Matty,

I'm fine thanks - hope you're well 🙂

• FIRSTNONBLANK is used as a tie-breaker (technique taken from here). If there were a tie for the top CityID, the TOPN function itself would return all of them (as a single-column table). Without FIRSTNONBLANK this would cause an error (as a measure can't return a table apart from the special case of 1-row/1-column). So FIRSTNONBLANK is used to return just the first value (alphabetically or numerically).
  Actually, since MINX/MAXX can be used with Strings now, another way of writing the tie-breaker measure is:
  

  Top Selling City =
  MINX (
      TOPN ( 1, VALUES ( YourTable[CityID] ), [% of total sales MEASURE] ),
      YourTable[CityID]
  )

• With the measure as I've written it, only the first CityID numerically (ascending) would be shown, so it is already doing what you've suggested.
  One way to return multiple tied CityID values would be to use CONCATENATEX:
  

  Top Selling City =
  CONCATENATEX (
      TOPN ( 1, VALUES ( YourTable[CityID] ), [% of total sales MEASURE] ),
      YourTable[CityID],
      ", ",
      YourTable[CityID]
  )

Cheers

Owen

[Matty]

Thanks Owen.  Explanation very clear.

Cheers,

Matty