Problem with Entity SQL

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C#

Hi All,

I am learning Entity Framework 4 from book.

And I try to make some Query with Entity SQL like this :

using (var context = new BAEntities())
{
    string str = "SELECT VALUE c " +
                 "FROM BAEntities.Contacts " +
                 "AS c " +
                 "where c IS NOT OF(BAModel.Customer)";

    ObjectQuery<Contact> qry = context.CreateQuery<Contact>(str);

    Console.WriteLine(qry.Count());
}

My query purpose is to take all Objects of Contact Type but not of Customer Type.
Where, Customer inherits from Contact

And I got the following error :


Type 'BAModel.Customer' could not be found. Make sure that the required schemas are loaded and that the namespaces are imported correctly. Near type name, line 1, column 64.

But, If I do query with LINQ to Entities like this :

ObjectQuery<Contact> qry = context.Contacts.Where(c => !(c is Customer));

then program can Run correctly.

So, why in Entity SQL BAModel.Customer is not found, whereas I ran the code within the same project in which the model is located.

Please help me in this regard.

Thanks in Advance.