This camp session will provide a fast-paced primer for writing Power BI query logic using the M programming language. The goal of this session is to give campers a stronger foundation for working directly with M code in the Advanced Editor when design queries for datasets in Power BI Desktop as well as for dataflows in the browser. Campers will learn how to design efficient queries using query folding as well as how to clean text values using the Text.Select function. Campers will be introduced to writing queries using complex M datatypes including lists, records, tables, functions and user-defined types and optimizing query logic using query folding. The session will demonstrate real-world examples of using dataset parameters, performing calculations across rows during query execution and writing reusable function queries. The session will also discuss how to avoid using dynamic datasources and privacy levels that prevent your queries from being able to run in the Power BI Service.
Campers should have previous experience working with Power Query in Power BI Desktop. It is recommended (but not required) that campers have experience working directly with M code in the Advanced Editor.