I am trying to build a RSL on my Power BI report. However, when I try to set up a many to many relationship (I don’t see how I can have a one-to-many relationship), I have this symbol that "breaks" the relationship :
What does it mean? The RSL won’t work with it.
Here are what the two tables look like :
There is no bi-directionnal filter relationship, no blank value in the CLE_HABILITATIONS column. I don’t see why… And impossible to find out what this icon means on stack overflow/google.
>Solution :
This is a limited relationship. From the current documentation:
A model relationship is limited when there’s no guaranteed "one" side. A limited relationship can happen for two reasons:
- The relationship uses a many-to-many cardinality type (even if one or both columns contain unique values).
- The relationship is cross source group (which can only ever be the case for composite models).
In the following example, there are two limited relationships, both marked as L. The two relationships include the many-to-many relationship contained within the Vertipaq source group, and the one-to-many cross source group relationship.
For import models, data structures are never created for limited relationships. In that case, Power BI resolves table joins at query time.
Table expansion never occurs for limited relationships. Table joins are achieved by using INNER JOIN semantics, and for this reason, blank virtual rows aren’t added to compensate for referential integrity violations.
There are other restrictions related to limited relationships:
- The RELATED DAX function can’t be used to retrieve the "one" side column values.
- Enforcing RLS has topology restrictions.
In Power BI Desktop model view, you can interpret a relationship as being limited. A limited relationship is represented with parenthesis-like marks ( ) after the cardinality indicators.
