Data type changes in Power BI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a data type in Power BI?

A data type tells Power BI what kind of data is stored in a column, like numbers, text, or dates. It helps Power BI understand how to use the data.

beginner

Why do we need to change data types in Power BI?

Changing data types ensures data is used correctly. For example, numbers should be numbers to do math, and dates should be dates to sort or filter by time.

beginner

How can you change a column's data type in Power BI Desktop?

In Power BI Desktop, go to the Data view, select the column, then use the Data Type dropdown in the ribbon to pick the right type like Text, Whole Number, or Date/Time.

beginner

What happens if you try to do math on a text data type column?

Power BI will not calculate correctly because text is treated as words, not numbers. You must change the data type to a number to do math.

intermediate

Can changing data types affect your reports?

Yes, changing data types can fix errors or improve performance. But if done wrong, it can cause wrong results or break visuals.

Which data type should you use for a column with dates in Power BI?

A Boolean

B Text

C Whole Number

D Date/Time

Dates should use the Date/Time data type so Power BI can sort and filter by time correctly.

What is the first step to change a column's data type in Power BI Desktop?

A Open Power Query Editor

B Go to the Data view and select the column

C Create a new measure

D Refresh the data

You first select the column in Data view to change its data type using the ribbon options.

If a number column is mistakenly set as Text, what problem might occur?

A Math calculations will not work correctly

B Power BI will automatically fix it

C You can still do math without issues

D The column will disappear

Math calculations require numeric data types; text data types prevent correct math operations.

Which of these is NOT a common data type in Power BI?

A Whole Number

B Currency

C Image

D Boolean

Image is not a standard data type for columns in Power BI; common types include Whole Number, Currency, and Boolean.

What can happen if you change a data type incorrectly?

A Your report visuals might show wrong data

B Power BI will delete your data

C Nothing will change

D Power BI will automatically revert it

Incorrect data type changes can cause wrong results or break visuals in your reports.

Explain why changing data types is important in Power BI and give an example.

Think about what happens if you try to add text instead of numbers.

Describe the steps to change a column's data type in Power BI Desktop.

Focus on the interface steps in Power BI Desktop.