For example, an Employee object might propagate its primary key to an EmployeePhoto object. Objects only propagate their primary key values if the corresponding values in the destination object aren't already set. Throws an exception if the receiver is flattened. See the class description for considerations in setting this flag. Sets the dictionary of auxiliary data, which your application can use for whatever it needs.
Returns null if the relationship is flattened.
Your application can use this data for whatever it needs. A name is also invalid if the receiver's EOEntity already has an EORelationship with the same name, or if the model has a stored procedure that has an argument with the same name. A mandatory relationship is one in which the target of the relationship is required. Returns null to indicate success.