Forum Discussion

Toerstad's avatar
Toerstad
Advocate I
6 years ago
Solved

Agg-tables - What is the difference between Count and Count Rows, and can you use distinctcount?

When you mark a table as an aggregate table in Power BI, you can map columns in the aggregate table to the details-table using summary functions like: Count, GroupBy, Max, Min, Sum and Count Rows. I...
Need Help
  • v-juanli-msft's avatar
    v-juanli-msft
    6 years ago

    Hi Toerstad 

    CountRows->calculate the rows of a table

    Count->calculate the rows of a column

    DISTINCTCOUNT->calculate the distinct rows of a column

     

    They all ignore the blank or empty strings.

    COUNTA would consider blank or empty strings.

     

    COUNTX, COUNTAX can calculate for measures.

     

    You could learn more here:

    A video: https://www.youtube.com/watch?v=V8wYTjKyvgk

    DAX Reference:

    https://docs.microsoft.com/en-us/dax/count-function-dax

     

    Best Regards
    Maggie

     

    Community Support Team _ Maggie Li
    If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

v-juanli-msft's avatar
v-juanli-msft
Community Support
6 years ago

Hi Toerstad 

CountRows->calculate the rows of a table

Count->calculate the rows of a column

DISTINCTCOUNT->calculate the distinct rows of a column

 

They all ignore the blank or empty strings.

COUNTA would consider blank or empty strings.

 

COUNTX, COUNTAX can calculate for measures.

 

You could learn more here:

A video: https://www.youtube.com/watch?v=V8wYTjKyvgk

DAX Reference:

https://docs.microsoft.com/en-us/dax/count-function-dax

 

Best Regards
Maggie

 

Community Support Team _ Maggie Li
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

  • Toerstad's avatar
    Toerstad
    Advocate I
    6 years ago

    Hi.

    Thank you for your reply. 

    I have a fairly decent grip on how the regular DAX expressions work, but I feel how this is implemented in PowerBI aggregation tables are poorly documented on docs.

    I assume they work the same way as per usual DAX, but this is an assumption.

    As I mentioned, I would also like to see other summarization functions like DISTINCTCOUNT, is there any support for this? Will there be?

    As i write this I realize that a COUNTROWS on an aggreagate table GroupedBy by the column i want to DISTINCTCOUNT might be an option. But – then this would bloat my PBIX due to the high cardinality of my column.