How To Use DAX Query View in Power BI Desktop

In this week's newsletter, we explore how to use the DAX Query View, a powerful feature in Power BI Desktop, to debug, modify, and enhance your DAX measures.

This feature provides an intuitive way to see how your DAX measures are interconnected, test DAX queries, and streamline troubleshooting without affecting your report view.

Enabling the DAX Query View

The DAX Query View is currently a preview feature in Power BI Desktop, introduced in February 2024. To enable it:

• Go to Options in Power BI Desktop.
• Navigate to Preview Features and select DAX Query View.
• Restart Power BI Desktop to enable this feature.

What is the DAX Query View?

The DAX Query View allows you to view, debug, and modify DAX measures within Power BI Desktop. It provides an easy way to see measure lineages, where measures are used in other measures, and how they contribute to your report.

The DAX Query View is particularly useful when working with complex models where multiple measures are interdependent.

Using the DAX Query View

Evaluating Measures

Once the DAX Query View is enabled, you’ll see a fourth option in the left-hand pane. You can evaluate any measure by right-clicking on it and selecting Quick Queries > Evaluate.

This will show the result of the measure unfiltered and ungrouped.

Defining and Evaluating Measures

To view both the result and the DAX code behind a measure, right-click on the measure and choose Quick Queries > Define and Evaluate.

This will display the DAX formula that defines the measure and the corresponding result.

Lineage and Debugging

For measures that depend on other measures, you can select Quick Queries > Define with References and Evaluate.

This view shows the entire lineage of a measure, revealing how it uses other measures. It’s an excellent tool for debugging complex DAX calculations without manually tracking dependencies.

Modifying Measures and Testing Changes

One of the best features of the DAX Query View is the ability to modify measures and test changes without directly affecting your model. You can make changes to a measure’s DAX formula, evaluate it, and then decide whether to save those changes.

For example, if you want to modify a calculation from using SamePeriodLastYear to using DateAdd and compare the results, you can do so directly in the DAX Query View.

Once satisfied with the result, click Update Model to apply the changes to your model.

Benefits of Using DAX Query View

• Debugging: Quickly identify issues in complex DAX measures by tracing their dependencies.
• Live Testing: Modify DAX code and instantly see the results without affecting the original measure until you decide to save it.
• Better Insight: Understand the relationships between measures and improve your DAX knowledge.

Conclusion

The DAX Query View is an invaluable tool for any Power BI developer working with complex models and DAX measures. It simplifies the debugging process, helps you visualize measure dependencies, and allows you to test changes before committing them. If you’re working with DAX on a regular basis, this feature will greatly enhance your workflow.