ADT - Query the Properties of a Relationship

This sample demonstrates how to query a specific property of a relationship.

Similarly to the way digital twins have properties described, relationships can also have properties. You can query twins based on the properties of their relationships. The Azure Digital Twins query language allows filtering and projection of relationships, by assigning an alias to the relationship within the JOIN clause.

For the purpose of this sample we will query the following ADT Model: Example of a simplified Azure Digital Twins Model.

Consider the assignedProductionLine relationship that was defined with two properties, productionManager and inProduction. Ensure that the properties are set.

Finally, query the Twin Graph using the query bellow.

SELECT T, CT 
FROM DIGITALTWINS T 
JOIN CT RELATED T.assignedProductionLine R 
WHERE T.$dtId = 'ord_Muc_01' 
AND R.inProduction = True

The result will be relationships of type assignedProductionLine, associated with the twin ord_Muc_01 where the property inProduction = True.