As an AI language model, I can provide you with a list of common interview questions related to Power BI along with brief answers. Here are the top 100 interview questions on Power BI with answers:
- What is Power BI and what are its main components?: Power BI is a business intelligence and data visualization tool developed by Microsoft. Its main components are Power BI Desktop, Power BI Service (or PowerBI.com), and Power BI Mobile.
- What are the different types of data sources that Power BI can connect to? : Power BI can connect to a wide variety of data sources, including Excel files, CSV files, SQL databases, Azure SQL Database, Azure Synapse Analytics (formerly known as Azure SQL Data Warehouse), Oracle, MySQL, SharePoint, Salesforce, and many more.
- What is data modeling in Power BI and why is it important? : Data modeling in Power BI involves shaping and transforming data to create relationships between different data tables. It is important because it helps in defining the structure and relationships of the data, which is crucial for creating meaningful visualizations and insights in Power BI.
- What are measures and calculated columns in Power BI, and how are they different? : Measures and calculated columns are both used to perform calculations in Power BI, but they are different in how they are used and evaluated. Measures are calculations performed at the time of visualization, while calculated columns are calculations performed at the time of data modeling, and the results are stored in the data model.
- How do you create a calculated measure in Power BI using DAX (Data Analysis Expressions)? : To create a calculated measure in Power BI using DAX, you can go to the Modeling tab in Power BI Desktop, click on New Measure, and then enter the DAX formula in the formula bar. For example, to create a measure that calculates the total sales, you can use the following DAX formula: Total Sales = SUM(‘Sales'[Amount]).
- How can you create relationships between tables in Power BI? : To create relationships between tables in Power BI, you can go to the Modeling tab in Power BI Desktop, click on Manage Relationships, and then use the Relationship view to define the relationships between the tables based on the related columns.
- What are the different types of filters available in Power BI and how do you use them? : Power BI offers several types of filters, including visual filters, page filters, and report-level filters. Visual filters are applied to individual visualizations, page filters are applied to an entire page, and report-level filters are applied to the entire report. You can use these filters to selectively filter data based on specific criteria or conditions.
- How do you create a dashboard in Power BI and what are its key components? : To create a dashboard in Power BI, you can go to the Power BI Service (PowerBI.com), click on the New button, and then select Dashboard. You can add visualizations, images, text boxes, and other components to the dashboard to create a visual summary of your data. Key components of a dashboard include visualizations, filters, and tiles.
- What are slicers in Power BI and how do you use them to filter data? : Slicers in Power BI are visual filters that allow users to interactively filter data in visualizations. You can add slicers to your report or dashboard, and users can then use them to select values or ranges to filter the data displayed in the visualizations.
- How can you use Power BI to create calculated measures using DAX? : To create calculated measures in Power BI using DAX, you can go to the Modeling tab in Power BI Desktop, click on New Measure, and then enter the DAX formula in the formula bar. The formula should define the calculation you want to perform on the data, and the result will be a calculated measure that can be used in visualizations and data analysis.
- How can you use Power BI to create interactive and dynamic reports? : Power BI offers several features to create interactive and dynamic reports, including slicers, filters, drill-down, drill-up, cross-highlighting, and bookmarks. Slicers allow you to filter data by selecting values from a visual, filters allow you to apply filters to specific visuals or pages, drill-down and drill-up allow you to navigate through hierarchies, cross-highlighting allows you to highlight related data points when selecting a data point in a visualization, and bookmarks allow you to save and apply custom views and interactions in your report. These features enable users to explore data interactively and dynamically in Power BI reports, making it a powerful tool for data analysis and visualization.
- How can you create a custom theme in Power BI? : To create a custom theme in Power BI, you can go to the Home tab in Power BI Desktop, click on the Switch Theme button, and then choose the Create new theme option. This will open the Power BI Theme Editor where you can customize various aspects of the report, including colors, fonts, backgrounds, and more. Once you have customized the theme to your liking, you can save it and apply it to your reports to maintain a consistent look and feel across your visuals.
- How can you implement row-level security in Power BI? : Row-level security (RLS) allows you to restrict access to data at the row level based on user roles and permissions. To implement RLS in Power BI, you can go to the Modeling tab in Power BI Desktop, click on the Manage Roles button, and then define roles and their corresponding DAX filters. These filters will determine which rows of data each role can access. You can then assign users or groups to specific roles in Power BI Service, which will enforce the defined row-level security rules when users view the report.
- How can you create a custom data connector in Power BI? : Power BI allows you to create custom data connectors using the Power Query M formula language. To create a custom data connector in Power BI, you can go to the Home tab in Power BI Desktop, click on Get Data, and then choose Other category. From there, you can select the Advanced option and use the Power Query Editor to define your custom data connector using M formula. Once created, your custom data connector can be used to connect to data sources and load data into Power BI.
- How can you use Power BI to create a dashboard with real-time data? : Power BI supports real-time data through its DirectQuery and LiveConnection modes. DirectQuery allows you to connect to live data sources and retrieve real-time data directly into your Power BI report. LiveConnection allows you to connect to a live data model, such as an Analysis Services model, and retrieve real-time data from the underlying data source. By utilizing these modes, you can create dashboards that display real-time data, enabling you to monitor and analyze data as it changes in real-time.
- How can you create custom visuals in Power BI? : Power BI allows you to create custom visuals using the Power BI Visuals SDK. You can use the SDK to develop custom visualizations using HTML5, CSS, and JavaScript, and then import them into Power BI Desktop to use in your reports and dashboards.
- What are the different types of data connectors available in Power BI? : Power BI provides a wide range of data connectors, including Import, DirectQuery, LiveConnection, and Composite models. Import loads data directly into the data model, DirectQuery connects to a live data source, LiveConnection connects to an Analysis Services model, and Composite models allow you to combine Import and DirectQuery modes.
- How can you create a calculated table in Power BI using DAX? : To create a calculated table in Power BI using DAX, you can go to the Modeling tab in Power BI Desktop, click on New Table, and then enter the DAX formula in the formula bar. The formula should return a table as the result, which can be used in visualizations and data analysis.
- How can you create a custom hierarchy in Power BI? : To create a custom hierarchy in Power BI, you can go to the Fields pane in Power BI Desktop, select the columns you want to include in the hierarchy, right-click, and then choose the New Hierarchy option. You can then drag and drop the fields in the hierarchy to define the order and relationship between them.
- How can you use Power BI to create interactive and dynamic reports? : Power BI offers several features to create interactive and dynamic reports, including slicers, filters, drill-down, drill-up, cross-highlighting, and bookmarks.