DistinctCount IF?

[Anonymous]

Hi All,

I'm new to Power BI (and DAX) coming from Tableau.

I've got a question regarding the DiscountCount function.

I need to calculate a percentage of orders that include a certain item. The way my data is structured is line items on every order for the last year. (Example: If one order has three items on it, three lines are returned for that order each line with a specific item).

I'd like to create a measure that give me the sum of a distinct count of order numbers but only if they include a certain item number. I can't use the filter function because I'd need to compare the afore mentioned measure to a count of all distinct orders.

This seems like something that should be very doable, I'm just can't wrap my head around it yet.

Thanks!

PS - Does anyone have any good resources (perferably books) that can get me into the swing of using DAX and Power BI?

[greggyb · Accepted solution]

CALCULATE(
    DISTINCTCOUNT( FactOrder[OrderNumber] )
    ,FactOrder[Line Item] = <certein item number>
)

[gp201641]

@greggyb  @Anonymous  I am trying to use your formula, but i am not sure where I am doing a mistake 

want to calculate distinct job number on gloss pack option or body colour option 

Here is the error 

[gp201641]

@greggyb  Can you please tell me where i am doing wrong, I tried to use your formula 

[Anonymous]

Worked perfectly! Thank you so much!

[Anonymous]

If you want to understand the reason behind that answer, check this out: http://www.powerpivotpro.com/2009/12/powerpivot-dax-calculate-is-a-supercharged-sumif/

Actually the title of that blog post is slightly misleading; CALCULATE is a supercharged WHATEVERIF. COUNTIF, SUMIF, DIVIDEIF, etc. depending on what kind of expression you feed into it. That whole blog is a fantastic resource for learning DAX, and they've got a great book as well.

[Anonymous]

Thank for the resource, I really appreciate it!