Problem Statement:
The customer service team wants to analyze the number of unique customers who have placed orders in the last quarter. They also need to identify the unique product categories purchased during that period for targeted marketing efforts.
Why DISTINCT is the Solution:
- In this scenario, DISTINCT {Syntax: DISTINCT(<columnName>) is well-suited because:
- It extracts unique values from a column, enabling calculations or analyses that rely on distinct entities (e.g., unique customers or product categories).
- It can be used in conjunction with other DAX functions like COUNTROWS, SUMX, or AVERAGEX for aggregate operations on unique values.
DAX Example:
Use Case 1: Counting Unique Customers: To count the unique customers who placed orders:
DAX:
DAX: Unique_Customer_Count = COUNTROWS(DISTINCT(Sales[CustomerID]))
Use Case 2: Total Sales by Unique Customers: To calculate total sales considering unique customers:
DAX:
DAX: Total_Sales_by_Unique_Customers = SUMX(DISTINCT(Sales[CustomerID]), CALCULATE(SUM(Sales[SalesAmount])))
Key Point:
DISTINCT is a great fit when you need to operate on unique values from a column, making it useful for counting, filtering, or performing aggregations that depend on deduplicated data. It is particularly effective for tasks like customer analysis, product categorization, or building dynamic visuals.