The Data Analysis Expressions (DAX) helps to work with ease with data models using formulas and expressions. DAX is used in many Microsoft products like Power BI and Power Pivot for Excel. DAX formulas helps in advanced calculations and queries on data in tabular data.
DAX formulas are essential for creating calculations in calculated columns and measures and securing your data by using row level filters.
DAX includes functions that can be used to perform calculations using dates and times, create conditional values, work with strings, perform lookups based on relationships, and perform recursive calculations.
Though they are like Excel functions, DAX formulas are different in some important ways that include:
A DAX function always references a complete column, or a table and we need to add filters if we want to use only particular values from a table or column.
DAX includes many functions that return a table, rather than a value. This table is used to provide input to other functions.
DAX functions include a variety of time-intelligence functions. For example, we can compare sums across parallel periods.
The various DAX functions can be grouped under the following categories.
Text Functions, Statistical Functions, Parent & Child Functions, Math & Trig Functions, Logical Functions, Information Functions, Filter Functions, Date And Time Functions and Time And Intelligence Functions
Our sections on DAX functions provides a basic introduction to the important functions in DAX.