Following the above Site I have created External LookUp relationship between "Orders and OrderDetails" What my question is how OrderId in OrderDetail object is exactly mapping to OrderId in Order Object, even though i select Order object as External Lookup but i haven't selected OrderId field to map. How is it mapping?.
My requirement is
1.I have External Case and External Account objects (Not Standard Case, Not Standard Account).
2.Account have fileds ID, Name, etc..., Case have AccountId, CaseNumber..etc..,
3.Now i want create External LookUp relationship between AccountId field in CASE and ID field in Account
4.So, that Case should be related list of Account