Dynamic Column Metrics

[TuckRhodes]

I am trying to recreate the 'Column Quality' Power Query feature in Power BI. For example, I would like to get a null or blank percentage based on a column that the user has chosen from a field parameter that contains all of the column names. Here is my current DAX:

Null Percentage =

VAR selected_column = SELECTEDVALUE('Column'[Column Fields])

VAR num_rows = COUNTROWS(Table1)

VAR num_null = COUNTROWS(FILTER(Table1, ISBLANK(selected_column))))

RETURN DIVIDE(num_null, num_rows)

Currently, this measure returns 100% all the time which I know is incorrect. I have tried not using the select_column variable thinking maybe it was a caching issue but that did not work.

Thanks for any and all help!

[Ray_Minds]

Please take look in the below highlighted calculation. You need change with this query. I hope that would be helpful.
Null Percentage =
VAR selected_column = SELECTEDVALUE('Column'[Column Fields])
VAR num_rows = CALCULATE (COUNTROWS(Table1), All(Table1))
VAR num_null = COUNTROWS(FILTER(Table1, ISBLANK(selected_column))))
RETURN DIVIDE(num_null, num_rows)

[TuckRhodes]

Unfortunately, this is still giving me the same result.

[Anonymous · Accepted solution]

Hi @TuckRhodes ,

The most common way to do this is to create measures for each column similar to the one below and then bind them to the field parameters:

Column 1 = 
VAR __num_null = CALCULATE(COUNTROWS('Table1'),ISBLANK('Table1'[Column1]))
VAR __num_rows = COUNTROWS('Table1')
RETURN DIVIDE(__num_null,__num_rows) + 0

The pbix file is attached for reference.

Best Regards,
Gao
Community Support Team

If there is any post helps, then please consider Accept it as the solution  to help the other members find it more quickly.
If I misunderstand your needs or you still have problems on it, please feel free to let us know. Thanks a lot!

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[TuckRhodes]

I was worried about that, but I am beginning to think that is the only way. I'm going to have quite a few columns to do this for which is why I was trying to avoid making the measure for each column but maybe that is the only way.