面试题与答案

Power BI Desktop is a standalone application for creating Power BI reports, while Power BI Service is a cloud-based service for publishing, sharing, and collaborating on Power BI reports and dashboards.

Calculated columns in Power BI are created using Data Analysis Expressions (DAX) in Power BI Desktop. You can use DAX functions to define calculations based on existing columns in your data model.

Measures in Power BI are calculations applied to data in a report. Unlike calculated columns, measures are dynamic and can change based on user interactions. They are created using Data Analysis Expressions (DAX).

Power BI Gateway is used to connect Power BI reports and dashboards to on-premises data sources. It acts as a bridge between Power BI Service in the cloud and the data stored locally.

Power BI Report Server is an on-premises version of Power BI Service. While Power BI Service is a cloud-based solution, Power BI Report Server allows organizations to host and manage reports on their own servers.

Row-level security in Power BI allows you to restrict data access based on user roles. It is implemented using DAX filters to control which data users can see based on their role assignments.

A calculated table in Power BI is created using DAX expressions. You can define calculations based on existing tables or columns in the data model. The new table is then used in the report.

Power BI Dataflows allow users to extract, transform, and load (ETL) data into a Power BI dataset. It provides a way to centrally manage and reuse data preparation steps across multiple reports and dashboards.

Time intelligence in Power BI involves using DAX functions to analyze and compare data over time. Functions like TOTALYTD, SAMEPERIODLASTYEAR, and DATESBETWEEN are commonly used for time-based calculations.

The 'Drillthrough' feature in Power BI allows users to navigate from a summary report to a detailed report by clicking on a data point. It provides a way to explore data at a more granular level.

Calculated columns in Power Query are created using the 'Add Column' tab in Power Query Editor. You can use M language expressions to define calculations based on existing columns in the data.