DAX Language Learning Guide

Mastering DAX: From Zero to Hero Your visual guide to Data Analysis Expressions What is DAX?

DAX (Data Analysis Expressions) is a formula expression language used to create custom calculations in analytical tools like Power BI, Analysis Services, and Power Pivot in Excel.

It's not a programming language, but a collection of functions, operators, and constants that can be used in a formula to calculate and return one or more values.

Its primary purpose is to operate on data models, rather than individual cells like in Excel.

Calculated Columns Calculated once during data refresh and physically stored in the model.

They operate in Row Context - the formula sees values only from the current row.

→ Use when: The result will be used in a filter or axis of a chart.

The calculation is static and depends on the row.