If you just choose 'Default' in this case, you should be able to proceed without problems during runtime. The OpenAccess runtime automatically finds the primary key property of the corresponding class and relates the foreign key of "d" to that primary key. The other way to achieve more precise definition during design time would be, if you have your tables defined, to use the relational view of the association editor where you could chose the correct column of the "b" table. That is however, not necessary for scenarios where you have a single id field declared in the base class.
the Telerik team
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