Which DAX function should you use to create a virtual relationship between two tables without a physical relationship?

• A. CROSSFILTER()
• B. PATH()
• C. TREATAS()
• D. USERELATIONSHIP()

Answer: (C)

Understanding how to propagate filters without a physical relationship is key. TREATAS lets you map values from one column into another column so the engine evaluates as if a relationship existed, all within your filter context. It doesn’t add any relationship to the model; it creates a virtual link during the calculation itself. You typically use it inside CALCULATE (or similar) to send a set of values from one table’s column to another table’s column, enabling the desired cross-table filtering.

For example, if you have Orders with CustomerID and a separate Customers table with CustomerID but no relationship, you can total Sales by applying: CALCULATE(SUM(Orders[Amount]), TREATAS(VALUES(Customers[CustomerID]), Orders[CustomerID])). This makes the Customers’ IDs affect the Orders rows as if there were a real relationship.

This differs from other options: CROSSFILTER requires an existing relationship to change how filters flow; PATH is for traversing hierarchies in parent-child structures; USERELATIONSHIP activates an existing relationship within a calculation. TREATAS uniquely creates the virtual link without altering the data model.