Microsoft Power BI DAX Formulas and Functions

Question 1

What does the DAX function CALCULATE() do?

Accepted Answer

Evaluates an expression in a modified filter context

Answer

CALCULATE() evaluates a DAX expression after applying the specified filter modifications to the filter context.

Question 2

What is the result of the DAX expression SUMX(Sales, Sales[Quantity] * Sales[Price])?

Accepted Answer

The row-by-row product of Quantity and Price, summed across all rows

Answer

SUMX iterates over each row in the Sales table, multiplies Quantity by Price, and then sums all the resulting values.

Question 3

What does ALL() do when used inside CALCULATE()?

Accepted Answer

Removes filters from the specified table or columns

Answer

ALL() removes any existing filters on the specified table or columns, allowing the measure to calculate across all data regardless of slicers.

Question 4

What is the difference between DISTINCTCOUNT() and COUNT() in DAX?

Accepted Answer

DISTINCTCOUNT counts unique non-blank values; COUNT counts all non-blank values including duplicates

Answer

DISTINCTCOUNT counts the number of unique, non-blank values in a column, while COUNT counts all non-blank values including duplicates.

Question 5

In DAX, what does the RELATED() function do?

Accepted Answer

Returns a value from a related table by following an existing relationship

Answer

RELATED() follows an existing many-to-one relationship from the current row context to retrieve a value from a related table.

Microsoft Power BI Practice Test