Power BI Course
Power Query, data modeling, DAX, visuals, dashboards and Power BI Service - from first import to a published report.
View course →Power BI Interview Questions
Questions grouped by topic with the idea behind a good answer.
Modeling
Why a star schema? Simpler relationships, faster queries and easier DAX than one wide table. What causes wrong totals? Many-to-many relationships, duplicate keys or the wrong filter direction.
DAX
Explain filter context. The set of filters applied to a calculation by slicers, visuals and relationships. Difference between SUM and SUMX? SUM aggregates a column; SUMX evaluates an expression row by row, then sums. How do you get last year’s value? SAMEPERIODLASTYEAR or DATEADD on a marked date table.
Power Query
Merge vs append? Merge joins columns from another table by key; append stacks rows. What is query folding? Pushing transformations back to the source database.
Visuals and Service
How do you choose a visual? Start from the question: comparison, trend, composition or distribution. What is row-level security? Roles that filter data by user.
Build the underlying skills in the Power BI course and DAX course.
Related courses
Power BI DAX Course
Measures, filter context, CALCULATE, time intelligence and iterators - the calculation layer of Power BI.
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Tell us your background and goal, and we will suggest the right starting point - Excel, Power BI or the full Excel + Power BI program.