Handling null and blank values in Power BI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the difference between null and blank in Power BI?

Null means no data exists at all, like an empty cell in a database.<br>Blank means a value is intentionally left empty or missing but recognized by Power BI as a blank value.

beginner

How does the DAX function ISBLANK() help when handling missing data?

ISBLANK() checks if a value is blank and returns TRUE if it is. It helps to identify and handle blanks in calculations or filters.

intermediate

What does the DAX expression COALESCE([Sales], 0) do?

This expression returns the [Sales] value if it exists; otherwise, it returns 0. It replaces blanks with zero to avoid errors or blanks in reports.

beginner

Why is it important to handle null and blank values in Power BI reports?

Handling nulls and blanks ensures accurate calculations, prevents errors, and improves report readability by avoiding confusing empty spaces.

intermediate

Which DAX function can replace blank values with a specific text like "No Data"?

IF(ISBLANK([Column]), "No Data", [Column]) replaces blanks with "No Data" while keeping other values unchanged.

What does the DAX function ISBLANK() return when the value is not blank?

A TRUE

B FALSE

C Blank

D Error

ISBLANK() returns FALSE when the value is not blank.

Which DAX function can you use to replace null or blank values with a default value?

A FILTER()

B ISBLANK()

C SUM()

D COALESCE()

COALESCE() returns the first non-blank value from its arguments, useful for replacing blanks.

In Power BI, what does a null value usually represent?

A No data or missing value

B A zero number

C An empty string

D A text value

Null means no data or missing value in the dataset.

Which DAX expression correctly replaces blank sales values with zero?

A IF(ISBLANK([Sales]), 0, [Sales])

B ISBLANK([Sales])

C SUM([Sales])

D FILTER([Sales], [Sales] <> BLANK())

This expression checks if sales is blank and replaces it with zero.

Why should you handle blank values in your Power BI visuals?

A To make reports slower

B To increase file size

C To avoid confusing empty spaces and errors

D To hide all data

Handling blanks improves report clarity and prevents calculation errors.

Explain how you can identify and replace blank values in a Power BI report using DAX.

Think about checking blanks first, then choosing what to show instead.

Describe why handling null and blank values is important for accurate and clear Power BI reports.

Consider what happens if blanks are ignored in calculations or visuals.