What is Filter used here for?

[spagad6263]

I've a table [test-data], and I would like to count how many records with field [PRE_CHECK] = "Y"). I've created measure as below. The difference is the second one has Filter, while the first one doesn't. They return same number of records. Just wondering what Filter is used here, and what difference it will make? Btw, the seconed one was written by anothre developer. Thanks.

mPre_Check = CALCULATE(DISTINCTCOUNT('test-data'[INVOICE_GUID]),'test-data'[PRE_CHECK] = "Y")

mPre_Check = CALCULATE(DISTINCTCOUNT('test-data'[INVOICE_GUID]),FILTER('test-data', 'test-data'[PRE_CHECK] = "Y"))

[spagad6263]

Thanks both for the advice.

[Ashish_Mathur · Accepted solution]

Hi,

The FILTER() function is of no use in this scenario because yours is a simple filter condition (not a rich filter condition).  A rich filter condition is where you compare a measure to a measure, a measure to a column or a column to a column.  The second trigger for a filter is where you want to give precedence to the selection made in the slicer or to the field dragged in the rows/columns of a visual.  So in your example if you create a slicer for PRE_CHECK where the user selects "N" and you want the calculation to use "N" rather than "Y".  The FILTER() function gives precedence to the user selection rather than the filter condition mentioned in the CALCULATE() function. 

[JorgePinho]

Check this https://stackoverflow.com/questions/72000696/why-calculate-is-not-modifying-filter-context-when-used... and this https://docs.microsoft.com/en-us/dax/best-practices/dax-avoid-avoid-filter-as-filter-argument