Calculate distinct value only if additional condition is true DAX formula

[WorkHard]

Hi,

I'm trying to count the number of resources that are assigned to a Project.

A simple distinct count wouldn't work because there are instances where a resource is assigned in the same period but on a different Project.

Say I have:

Resource  ProjectNr  Desired Result

Tool1           01                      1

Tool1           01                      0

Tool2           02                      1

Tool3           03                      1

Tool1           04                      1

The desired result would be 4. 

This needs to be a DAX formula and it needs to be a column that I can reference in a table. 

The way I'd solve this in excel would be to create an "ID" out of the combination of Resource+ProjectNr Column and then only count the first occurrence: 

A                     B =COUNTIF($A$1:$A1,$A1)=1)+0

Tool101          1

Tool101          0

Tool202          1

Tool303          1

Tool104          1

[Icey · Accepted solution]

Hi @WorkHard ,

Try this:

1. Add an Index column in Power Query Editor.

2. Create a column.

First Instance =
IF (
    COUNTROWS (
        FILTER (
            'Table',
            'Table'[Resource] = EARLIER ( 'Table'[Resource] )
                && 'Table'[ProjectNr] = EARLIER ( 'Table'[ProjectNr] )
                && 'Table'[Index] <= EARLIER ( 'Table'[Index] )
        )
    ) = 1,
    1,
    0
)

Best Regards,

Icey

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

[WorkHard]

Thanks Icey,

This would work except I'm stuck down a rabbit hole trying to create an index column. I can't just use query editor to add an index column because I'm in Live mode that doesn't have a query.

Unsure how many more helper columns I need to create to get this to work. RANKX will rank the same number in my case which means I need to create another extra column as some sort of ID....

Update:

Thank you both for your help, I ended up using Icey's solution and created an index column using 2 additional columns:

First Column (RND) to create a random number for each row

Second Column (Index) to create an index number based on the random values

RND = RAND()


Index = RANKX('TableName',[RND],[RND],ASC,Dense)

[MFelix]

Hi @WorkHard 

Did you tried the measure I have post before? 

[WorkHard]

Mfelix,

Yes but unfortunately a measure wouldn't work in my situation. I'm summarizing a table and I'm creating a UNION with another table (cache old data tabke) vs (live data table) and this numbering needs to be a column, not a measure.

[MFelix]

If your base is a table (independently of the way it's built) you can create a measure. You can even have measures based on temporary tables.

If you can share more details or a mockup file I can try and help you achieve it.

[MFelix]

Hi @ WorkHard,

Be aware that DAX measures are based on context so depending on the visualisation and columns or slicers filters you use you can get different results.

In this case you can do a measure (no need to have a column) similar to this

Count of tools = COUNTROWS( SUMMARIZETABLE(TABLE,Table[Project], "Tools", Distinct(Table[Tool]))

Made this measure by heart may need some adjustments. On cellphone not computer 😂