SUMX Over Multiple Columns

[cr731]

I am using SUMX to sum a calculation by Order Number in my table, and I want to add a new calculation that iterates over both Order Number and Item Number in my table, but having trouble doing so.

My table looks something like

[TABLE="class: grid, width: 500"]
<tbody>[TR]
[TD]Date
[/TD]
[TD]Order Number
[/TD]
[TD]Item Number
[/TD]
[TD]Other Columns...
[/TD]
[TD]Sales
[/TD]
[/TR]
[TR]
[TD]4/1/2018
[/TD]
[TD]789
[/TD]
[TD]ABC
[/TD]
[TD]...
[/TD]
[TD]100
[/TD]
[/TR]
[TR]
[TD]4/1/2018
[/TD]
[TD]789
[/TD]
[TD]DEF
[/TD]
[TD]...
[/TD]
[TD]50
[/TD]
[/TR]
</tbody>[/TABLE]

My current formula is

SUMX( DISTINCT(Table[Order Number]), [MyMeasure] )

I'd like to have this calculation run over the combination of Order Number and Item Number. I'd prefer to not have to create a calculated column concatenating Order Number and Item Number if possible. I'm stuck because it seems like DISTINCT only takes a single column.

Thanks

 

[gazpage]

SUMX (
    SUMMARIZE ( Table[Order Number], Table[Item Number]),
    [MyMeasure]
)

 

[gazpage]

SUMX (
    SUMMARIZE ( Table, Table[Order Number], Table[Item Number]),
    [MyMeasure]
)