Writing DAX Measures in the Power BI Service with Microsoft Fabric

In this Pragmatic Works training session, Angelica Choo Quan introduces an exciting new feature for Power BI users—the ability to write DAX measures directly within the Power BI Service. Powered by Microsoft Fabric, this enhancement expands the data modeling capabilities traditionally found only in Power BI Desktop, making analysis and reporting more flexible than ever.

What is Microsoft Fabric?

Microsoft Fabric is an all-in-one analytics platform that integrates experiences across:

• Data engineering
• Data Factory and Azure Data Factory
• Data science
• Data warehousing
• Real-time analytics
• Power BI

Fabric provides a “OneLake” environment where structured and unstructured data can be stored, managed, and analyzed seamlessly. For Power BI analysts, this means new opportunities to perform data modeling and write DAX measures without leaving the Power BI Service.

Getting Started with Fabric in Power BI Service

To begin modeling data and creating measures in the Power BI Service, users need to:

1. Create or enable a Microsoft Fabric trial account.
2. Enable the Fabric trial license within one of their workspaces.
3. Access a Fabric Lakehouse, which serves as the data architecture for storing and analyzing large volumes of information.

Angelica notes that the Lakehouse is critical, acting as a scalable platform where users can combine structured and unstructured data. In this example, she works with the well-known Adventure Works Lakehouse.

Building a Power BI Dataset from a Lakehouse

Once inside the Fabric workspace, the next step is to create a new Power BI dataset. Angelica demonstrates how to:

• Select the Adventure Works Lakehouse as the data source.
• Choose relevant tables—such as Product Dimension, Internet Sales Fact, and Date Dimension.
• Generate the dataset, which prepares the model for further development in the Power BI Service.

From here, relationships can be established among the tables, similar to what is done in Power BI Desktop. Angelica sets up a star schema by creating relationships between the Date and Sales tables, as well as between the Product and Sales tables. Cardinality and cross-filter directions are automatically assigned, making the modeling experience very familiar to Power BI Desktop users.

Writing DAX Measures in the Service

With relationships in place, it is time to write DAX measures directly in the Power BI Service. Angelica illustrates the process by creating a simple measure called Total Sales:

• She selects the option to create a DAX measure, which opens the formula bar.
• Using the SUM function, she defines Total Sales = SUM(FactInternetSales[SalesAmount]).
• The measure is validated and saved successfully within the dataset.

This measure can then be used in reports just as it would in Power BI Desktop. Angelica quickly demonstrates how to insert the measure into a new report, confirming that it calculates the correct totals across all products and territories.

Connecting Power BI Desktop to Fabric Datasets

Another advantage of this new capability is the ability to connect Power BI Desktop to the dataset created in Fabric. By launching a new desktop report and connecting to the dataset via the OneLake data hub, analysts can:

• Leverage the star schema and measures built in the Power BI Service.
• Use Direct Lake mode for enhanced performance.
• Gain the speed of Import mode combined with the flexibility of Direct Query.

While the live connection does not provide access to the data view in Power BI Desktop, users can still work within the report view to build out visualizations and analyses with confidence.

Why This Matters for Analysts

For Power BI data analysts, the ability to write measures and perform modeling directly in the Power BI Service provides several benefits:

• Efficiency: No longer limited to Power BI Desktop, analysts can model and calculate directly online.
• Collaboration: Shared workspaces in Fabric mean multiple users can access, model, and extend datasets together.
• Performance: Direct Lake connections improve performance while maintaining flexibility.
• Simplification: Everything from storage to analysis can now occur within a single platform.

Conclusion

Angelica Choo Quan’s demonstration highlights the future of Power BI with Microsoft Fabric. Analysts can now create and manage DAX measures in the Power BI Service, simplifying workflows and enabling better collaboration across teams. With Fabric’s unified environment, organizations can handle vast data volumes, improve performance, and unlock new possibilities in data analysis.

For those interested in learning more, Pragmatic Works offers on-demand training covering Microsoft Fabric, Power BI, and related technologies. This is just one example of how Fabric is transforming the way analysts work with data in the Power BI ecosystem.

Don't forget to check out the Pragmatic Works' on-demand learning platform for more insightful content and training sessions on Fabric and other Microsoft applications. Be sure to subscribe to the Pragmatic Works YouTube channel to stay up-to-date on the latest tips and tricks.