SELECTEDVALUE and HASONEVALUE in Power BI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the DAX function SELECTEDVALUE do?

SELECTEDVALUE returns the single value when there is exactly one value selected in a column. If there are multiple or no values, it returns a default value you specify or blank.

beginner

How does HASONEVALUE differ from SELECTEDVALUE?

HASONEVALUE returns TRUE if exactly one distinct value is selected in a column, otherwise FALSE. It is a logical check, while SELECTEDVALUE returns the actual value or default.

beginner

Write a simple DAX expression using SELECTEDVALUE to get the selected product name or "No Product" if none or multiple are selected.

SelectedProduct = SELECTEDVALUE(Products[ProductName], "No Product")

intermediate

Why would you use HASONEVALUE in a measure?

Use HASONEVALUE to check if a filter or slicer has exactly one value selected. This helps to write conditional logic, like showing detailed info only when one item is selected.

beginner

What will SELECTEDVALUE(Column) return if multiple values are selected?

It returns blank (empty) unless you provide a default value as the second argument.

What does SELECTEDVALUE(Column, "Default") return if no value is selected?

A "Default"

B Blank

C Error

D First value in column

If no value or multiple values are selected, SELECTEDVALUE returns the default value you provide, here "Default".

Which function returns TRUE or FALSE based on whether exactly one value is selected?

A SELECTEDVALUE

B HASONEVALUE

C VALUES

D FILTER

HASONEVALUE returns TRUE if exactly one distinct value is selected, otherwise FALSE.

If you want to show a message when multiple products are selected, which function helps detect this?

A CALCULATE

B SELECTEDVALUE

C SUM

D HASONEVALUE

HASONEVALUE helps detect if exactly one product is selected. If FALSE, multiple or no products are selected.

What will SELECTEDVALUE(Product[Name]) return if exactly one product is selected?

A The selected product name

B Blank

C Error

D All product names

When exactly one value is selected, SELECTEDVALUE returns that value.

Which of these is a correct use of HASONEVALUE in a measure?

A SUM(Category[Sales])

B SELECTEDVALUE(Category[Name])

C IF(HASONEVALUE(Category[Name]), "One", "Many")

D FILTER(Category, HASONEVALUE(Category[Name]))

This expression checks if exactly one category is selected and returns "One" or "Many" accordingly.

Explain in your own words how SELECTEDVALUE and HASONEVALUE work and when you would use each.

Think about selecting one item vs checking if only one item is selected.

Describe a simple scenario in a report where using HASONEVALUE improves user experience.

Imagine a product detail page that only shows details if one product is chosen.