Handling relationships is an essential aspect of any data modeling exercise. If done correctly, it can save a lot of time and effort. Though Power BI offers many-to-many relationships, but at times it adds many complexities. And hence, experts advise caution while using many-to-many relationships in Power BI.
TREATAS offers a relatively simple solution in this case. Let us understand this by the following example.
Following are two sample tables:
Calculate the Estimate vs. Actual report for each Project & Team.
As we notice, both the Project Number and Team have multiple values in both the table. If we establish a relationship, it is many-to-many.
For this exercise, we do not establish any relationship between the two tables
We have added a Calendar table and linked the two tables on Date
Refer to the following article for adding a Calendar table in the data model
Creating Basic Calculations
Added two measures for getting the total of Estimate and Actual Hours
Estimate Hours = SUM(table1[Estimate]) Actual Hours = SUM(table2[Hours])
Creating Measures using TREATAS
TREATAS applies the result of a table expression as filters to columns from an unrelated table. It returns a table containing all the rows in column(s) that are in the expression.
Total Hours Team = CALCULATE( [Actual Hours], TREATAS(VALUES(table1[Team]),table2[Team]), TREATAS(VALUES(table1[Project_Number]),table2[PR_Number]) )
In the above example, TREATAS is doing the following:
· VALUES function creates a list of all unique Teams and Project Number from table1
· TREATAS creates a virtual many-to-one relationship on Teams and Project Number
I have used the measure in the table visual, which is producing the expected output