Microsoft Fabric Ontology (Preview) - Possible Relationship Resolution Bug
Title
Ontology Path Query returns incorrect VisitOccurrence records by matching entity key values instead of configured relationship mappings.
Environment
Microsoft Fabric, Ontology (Preview), OMOP CDM dataset, Lakehouse tables, Entity Types: Person and VisitOccurrence.
Objective
Create a relationship Person -> person_has_visit -> VisitOccurrence using visit_occurrence.person_id -> person.person_id.
Test Data
Person table contains person_id values 10 and 12. VisitOccurrence contains: (10,1001), (12,2001), (12,2002), (12,2003).
Expected Relationships
Person(10)->VisitOccurrence(1001); Person(12)->VisitOccurrence(2001), VisitOccurrence(2002), VisitOccurrence(2003).
Entity Configuration
Person entity key: person_id. VisitOccurrence entity key: visit_occurrence_id. Both entities bound directly to their corresponding key columns.
Relationship Configuration
Relationship name: person_has_visit. Origin entity: Person. Target entity: VisitOccurrence. Mapping table: visit_occurrence. Mapping: Person key mapped to person_id column; VisitOccurrence key mapped to visit_occurrence_id column.
Expected Result
Path Query for Person(12) should return VisitOccurrence IDs 2001, 2002 and 2003.
Actual Result
Path Query returns an incorrect VisitOccurrence record. Earlier testing returned VisitOccurrence(12), whose properties showed person_id = 3. Therefore Person(12) was linked to a visit belonging to Person(3).
Why This Appears To Be A Bug
The source data contains no relationship between Person(12) and VisitOccurrence(12). The graph output appears inconsistent with both the configured relationship and the source data.
Troubleshooting Performed
Recreated VisitOccurrence table with a minimal dataset; rebound entity types; verified entity keys; recreated relationship; published ontology; used unique non-overlapping IDs to eliminate ambiguity.
Possible Causes
1. Relationship instances not regenerated after binding changes. 2. Ontology using stale/cached relationship data. 3. Path Query traversing using entity key/label equality instead of generated relationship instances. 4. Graph Explorer resolving nodes incorrectly.
Request To Fabric Team
Please confirm how relationship instances are materialized, whether Path Query uses relationship instances or labels/keys, whether ontology relationship data is cached after rebinding, and whether this is a known issue in Ontology Preview.
