DAX Query for Maximum Sales Calculation

Explanation of the Code Snippet

Overview

The provided code snippet is a DAX (Data Analysis Expressions) query commonly used in Power BI, Power Pivot, and Analysis Services. The code calculates the maximum SalesAmount for a specified date range and includes this calculation as a new column in the Sales table.

Code Breakdown

Below is the DAX code snippet:

EVALUATE
CALCULATETABLE (
    ADDCOLUMNS (
        Sales,
        "Max Sales Amount Date Range", 
        MAXX (
            FILTER (
                Sales, 
                Sales[Date] >= DATE(2022, 1, 1) && Sales[Date] <= DATE(2022, 12, 31)
            ), 
            Sales[SalesAmount]
        )
    )
)

Explanation by Components

1. EVALUATE

   EVALUATE

   • This keyword initiates a DAX query, signaling that it should return a table or a table expression as the result.

2. CALCULATETABLE

   CALCULATETABLE (

   • This function evaluates the expression in a modified filter context. In this case, it operates on the table returned by ADDCOLUMNS.

3. ADDCOLUMNS

   ADDCOLUMNS (
       Sales,

   • This function adds new columns to the table specified in its first argument (Sales). In this case, it adds a single new column.

4. Adding a New Column

       "Max Sales Amount Date Range", 

   • This part specifies the name of the new column to be added, here named "Max Sales Amount Date Range".

5. Calculating the Maximum Sales Amount

   MAXX (
       FILTER (
           Sales, 
           Sales[Date] >= DATE(2022, 1, 1) && Sales[Date] <= DATE(2022, 12, 31)
       ), 
       Sales[SalesAmount]
   )

   • MAXX: This iterator function returns the maximum value from a table expression.
   • FILTER: This function filters the Sales table based on the condition Sales[Date] >= DATE(2022, 1, 1) && Sales[Date] <= DATE(2022, 12, 31). This means only rows where the Date column falls within the year 2022 are considered.
   • Sales[SalesAmount]: This is the column from which the maximum value is derived.

6. Closing Parentheses

   )
   )

   • These close the ADDCOLUMNS and CALCULATETABLE functions.

Summary

The code snippet iterates over the Sales table and adds a new column named "Max Sales Amount Date Range". This new column contains the maximum SalesAmount for the specified date range (January 1, 2022, to December 31, 2022). The EVALUATE keyword at the beginning of the query is used to return the modified table.

Additional Example

For illustrative purposes, here is a similar example that calculates the sum instead of the maximum:

EVALUATE
CALCULATETABLE (
    ADDCOLUMNS (
        Sales,
        "Total Sales Amount Date Range", 
        SUMX (
            FILTER (
                Sales, 
                Sales[Date] >= DATE(2022, 1, 1) && Sales[Date] <= DATE(2022, 12, 31)
            ), 
            Sales[SalesAmount]
        )
    )
)

This query adds a column named "Total Sales Amount Date Range" which contains the sum of SalesAmount for the year 2022.