What Is DAX Syntax in Power BI?
DAX syntax is the set of rules for writing a valid DAX expression in Power BI: a name, an equals sign, a function call with parentheses, and Table[Column] references for any fields involved. It looks similar to an Excel formula but is built to operate across whole tables rather than single cells.
Anatomy of a DAX Formula
- Name and equals sign — e.g. Total Sales =
- Function name followed by parentheses — e.g. SUM(…)
- Table and column reference in square brackets — Table[Column]
- Commas separate arguments inside a function, not semicolons
Common DAX Syntax Rules
- Table names containing spaces are wrapped in single quotes, e.g. ‘Date Table'[Date]
- Text values are wrapped in double quotes, e.g. “West”
- Comments use // for a single line or /* */ for a block
- DAX is not case-sensitive, but uppercase function names (SUM, not sum) is the standard convention
Checking DAX Syntax for Errors
Power BI Desktop’s formula bar underlines a syntax problem in red as you type, and hovering shows a short description of the error. For longer or more complex DAX, the external tool DAX Studio offers more detailed syntax and performance checking than the in-app formula bar.
