Data Analysis Expressions (DAX) is both a query and functional language. The primary objective of DAX is to help organize, analyze, understand, and enhance data for analytics and reporting.
DAX helps in creating new information from existing information or data. The existing information can be at detail level, using DAX we can create information such as aggregated, summarized and so on.
Before implementing DAX in Power BI the following things need to be kept in mind:
Syntax of DAX :
The above pic is formula of DAX and details of syntax is shown below
A : is the measure name as 'Total Sales'.
B : The equals sign operator (=) indicates the beginning of the formula. When calculated, it will return a result.
C : The DAX function 'SUM' is used to add all the numbers in the Sales[SalesAmount] column.
D : Parenthesis () surround an expression containing one or more arguments. All functions require at least one argument. An argument passes a value to a function.
E :is the table name as 'Sales' which is been referred.
F : The referenced column [SalesAmount] in the Sales table. With this argument, the SUM function knows on which column to aggregate a SUM.
Some of the commonly used DAX Functions :