There is a limitation on mapping “Table per concrete class” associations to ERD.
Take “Table per subclass” as an example:
Saving either A, B or C will store a row in entity A, and the association will sync to D.AID foreign key reference A.
With “Table per concrete class”, all subclasses will store in their own table only, and independently. Saving B will not store a row in entity A, so the foreign key is invalid.
Please consider using other inheritance strategies.