USERELATIONSHIP Function (DAX)
Specifies the relationship to be used in a specific calculation as the one that exists between columnName1 and columnName2.
USERELATIONSHIP can only be used in functions that take a filter as an argument, for example: CALCULATE, CALCULATETABLE, CLOSINGBALANCEMONTH, CLOSINGBALANCEQUARTER, CLOSINGBALANCEYEAR, OPENINGBALANCEMONTH, OPENINGBALANCEQUARTER, OPENINGBALANCEYEAR, TOTALMTD, TOTALQTD and TOTALYTD functions.
USERELATIONSHIP uses existing relationships in the model, identifying relationships by their ending point columns.
In USERELATIONSHIP, the status of a relationship is not important; that is, whether the relationship is active or not does not affect the usage of the function. Even if the relationship is inactive, it will be used and overrides any other active relationships that might be present in the model but not mentioned in the function arguments.
An error is returned if any of the columns named as an argument is not part of a relationship or the arguments belong to different relationships.
If multiple relationships are needed to join table A to table B in a calculation, each relationship must be indicated in a different USERELATIONSHIP function.
If CALCULATE expressions are nested, and more than one CALCULATE expression contains a USERELATIONSHIP function, then the innermost USERELATIONSHIP is the one that prevails in case of a conflict or ambiguity.
Up to 10 USERELATIONSHIP functions can be nested; however, your expression might have a deeper level of nesting, ie. the following sample expression is nested 3 levels deep but only 2 for USEREALTIONSHIP: =CALCULATE(CALCULATE( CALCULATE( <anyExpression>, USERELATIONSHIP( t1[colA], t2[colB])), t99[colZ]=999), USERELATIONSHIP( t1[colA], t2[colA])).
The following sample shows how to override the default, active, relationship between InternetSales and DateTime tables. The default relationship exists between the OrderDate column, in the InternetSales table, and the Date column, in the DateTime table.
To calculate the sum of internet sales and allow slicing by ShippingDate instead of the traditional OrderDate you need to create a measure, [InternetSales by ShippingDate] using the following expression:
=CALCULATE(SUM(InternetSales[SalesAmount]), USERELATIONSHIP(InternetSales[ShippingDate], DateTime[Date]))
In PowerPivot: drag your new measure to the Values area in the right pane, drag the InternetSales[ShippingDate] column to the Row Labels area; you now have Internet Sales sliced by shipping date instead of by order date as is usually shown in these examples.
For this example to work the relationships between InternetSales[ShipmentDate] and DateTime[Date] must exist and should not be the active relationship; also, the relationship between InternetSales[OrderDate] and DateTime[Date] should exist and should be the active relationship.