TOPN function in Power BI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the TOPN function do in Power BI?

The TOPN function returns the top N rows of a table based on a specified expression or column, sorted in descending order by default.

beginner

Write the basic syntax of the TOPN function.

TOPN(<N_value>, <table>, <orderBy_expression>[, <order>[, <orderBy_expression>[, <order>]...]]), where N_value is how many rows to return.

intermediate

How can you change the sorting order in TOPN from descending to ascending?

Add the optional <order> argument with the value ASC after the <orderBy_expression> to sort ascending instead of the default DESC.

beginner

What type of value does the TOPN function return?

TOPN returns a table containing the top N rows based on the sorting criteria, not a single value.

intermediate

Can TOPN be used inside other DAX functions? Give an example.

Yes, for example, you can use TOPN inside CALCULATE to filter a table to the top N rows before aggregation.

What does the TOPN function return in Power BI?

A A table with the top N rows

B A single numeric value

C A text string

D A Boolean value

TOPN returns a table containing the top N rows based on the sorting criteria.

Which argument in TOPN specifies how many rows to return?

A <N_value>

B <orderBy_expression>

C <table>

D <order>

is the number of rows TOPN will return.

How do you sort the TOPN results in ascending order?

A TOPN always sorts ascending by default

B Add DESC after the orderBy_expression

C Use the SORT function instead

D Add ASC after the orderBy_expression

Adding ASC after the orderBy_expression changes the sort order to ascending.

Can TOPN be used inside CALCULATE to filter data?

A No, TOPN cannot be nested

B Yes, to filter to top N rows before aggregation

C Only with numeric columns

D Only in Power Query, not DAX

TOPN can be nested inside CALCULATE to filter data to top N rows.

What is the default sort order of TOPN if not specified?

A Random

B Ascending

C Descending

D Alphabetical

TOPN sorts in descending order by default.

Explain how the TOPN function works and when you might use it in a Power BI report.

Think about showing best-selling products or top customers.

Describe how to change the sorting order in TOPN and why that might be useful.

Consider when you want to see smallest sales instead of largest.