Record ownership with multiple master detail relationships
|Knowledge Article Number||000199273|
When a master detail relationship is created, records of the detail child object lose independent ownership, and assume the owner of their parent record. It is, however, possible to have more than one master detail relationship on the child object. If a record has two master parents, which is it's owner?
Each record can only ever have one owner (queues aside), so in a situation where you have more than one master-detail relationship, the first master-detail relationship created, becomes the primary relationship. Record ownership derives from the primary master-detail relationship. (Refer to "Considerations for Relationships")
This will be noted if, for example, a child record workflow rule wishes to create a task for the record owner - only the owner of the master record that makes up the primary relationship will be available. Interestingly if the child record workflow rule wishes to field up-date a record it will be able to target fields in all Master records, as it is not specifically dealing with its owner.
A situation may arise where the primary relationship has already been created, but it is desired that the ownership should derive from another master-detail relationship.The easiest way to resolve this issue is to remove the primary master detail relationship (by, say converting it to a look-up field) and then returning it (by converting it back to a master-detail relationship field). This has the effect of making the next master-detail relationship the "oldest", and as such it becomes the primary
Note: Conversion to look-up cannot be carried out when the parent has roll-up summary fields on the object, so these would need to be removed first if present