NHibernate Join and Restriction Criteria

Im trying to write an NHibernate criteria that effectively joins and restricts at the same time. My DB looks like this...

Cases ---> CustomerProducts <--- Customers Cases ---> CaseStatuses

Each case is associated with a customer product (Many cases to one product).

Each customer has a number of customer products (One customer has many customer products).

Each case additionally has a case status (one case status to many cases).

This has been mapped with XML files and the many 开发者_运维百科to many resolution between cases and customers (through customer products) has been resolved with a Sets<> in the CustomerProduct mapping meaning that the CustomerProduct entity has sets:

Customers

Cases

I then create a criteria typed to "Cases". The criteria I need to apply is....

1. Statuses IN [varioud status codes]. This has been acheived with....

   criteria.Add(Restrictions.In("CaseStatus.CaseStatusId", statuses));

2. Now I need to select only cases for a specific customer Id. I have tried...

   criteria.Add("CustomerProduct.Customer.CustomerId", customerId);

This doesnt work and NHibernate tells me that it cannot resolve the mapping to CustomerProduct.Customer.CustomerId.

Case has a property of a CustomerProduct object.

CustomerProduct has a property of a Customer object.

Customer has a property of CustomerId.

Any ideas why it wont work?

Thanks.

I think you need to create an alias for CustomerProduct.Customer:

criteria.CreateAlias("CustomerProduct", "customerProduct");
criteria.CreateAlias("customerProduct.Customer", "customer");
criteria.Add(Restrictions.Eq("customer.CustomerId", customerId));

I'm surprised the IN restriction worked without an alias. Here's a good article about performing join queries with the Criteria API.