Power Bi Dax Common Patterns

Column: computed row-by-row at refresh; stored in model; uses row context.
Measure: computed at query time; aggregates; uses filter context.

Total Sales := SUM(Sales[Amount])

Customers := DISTINCTCOUNT(Sales[CustomerId])

PY Sales := CALCULATE([Total Sales], SAMEPERIODLASTYEAR('Date'[Date]))

YoY % := DIVIDE([Total Sales] - [PY Sales], [PY Sales])

YTD Sales := CALCULATE([Total Sales], DATESYTD('Date'[Date]))

Bike Sales := CALCULATE([Total Sales], Products[Category] = "Bikes")

DIVIDE handles divide-by-zero gracefully (returns BLANK or 3rd arg). Slash returns infinity error.

Modifies filter context. Replaces or adds filters before evaluating its expression.

CALCULATE([Total Sales], ALL(Products[Category]))

ALLEXCEPT(Products, Products[Category]) — clears all filters on Products except Category.

%Total := DIVIDE([Total Sales], CALCULATE([Total Sales], ALLSELECTED()))