COUNT DISTINCT of expression evaluated at each row

[MrBlueSky2]

Hi all,

I need to count the distinct # of suppliers with products having a lower margin than a field parameter. Assuming the user selects 5% as parameter, I would like to have 2 for suppliers count from the example below (A and C).

Supplier	Product	Margin	COUNT DISTINCT
A	1	1%	A
A	2	2%	A
B	3	10%
C	4	4%	C

As the field parameter is dynamic, I cannot use a calculated column which will only use the default value of the parameter but not update dynamically.

In SQL, I would use something like COUNT DISTINCT (IF margin < parameter then supplier else null)
What DAX formula can I use for similar result?

Thanks in advance for your help

BR

[govind_021 · Accepted solution]

Hi @MrBlueSky2 
Please use below code

SuppliersWithLowMarginCount =
VAR LowMarginSuppliers =
CALCULATETABLE(
DISTINCT('Table'[Supplier]),
'Table'[Margin] < [FieldParameter]
)
RETURN
COUNTROWS(LowMarginSuppliers)

Regards
Govind Sapkade ( Data Analyst , Power BI PL 300 Certified , MS Fabric Enthusiast )
Linkdin : www.linkedin.com/in/govind-sapkade-845104225
Youtube : http://www.youtube.com/@govind_dataanalyst

[bhanu_gautam]

@MrBlueSky2 , Try using

dax
SuppliersWithLowMarginCount =
CALCULATE(
COUNTROWS(
DISTINCT('Table'[Supplier])
),
FILTER(
'Table',
'Table'[Margin] < [FieldParameter]
)
)