Can I lazy load a navigation property by delegating to a stored procedure in EF?

Question

I have the following customer class:

public class Customer 
{
    public long Id { get; set; }

    public virtual ICollection<Order> Orders { get; set; }
}

My database has Customers and Orders tables, but no foreign key relationships. Orders for a customer are obtained using a stored procedure that takes the customer ID and returns the order rows. I can't modify the database.

I know how to call the stored procedure from Entity Framework, but, is it possible to configure the DbContext using the fluent API so that accessing the Orders collection of a customer object would lazy load the entities via a call to the stored procedure?

I'm using the latest version of EF.

Candi

I'd be very surprised if you could, I think the only options are Eager Loading or creating a foreign key. – Katt

Can't you create a view which does the same? Why would you want lazy loading? Why do you need stored procedures? – Bureaucratize

Answer 1

No, you can't. Lazy loading is coded in the proxy object that EF creates (if possible), there's no way to intercept/configure the way proxies are generated.

It's not even possible to map the default read action of a DbSet to a stored procedure. It's always a query. Only create, update and delete can be mapped to stored procedures.

The reason (I think) is that stored procedures are not composable, so if in a complex LINQ query one entity would be mapped to a stored procedure (for reading) it wouldn't be possible to turn the query into one SQL statement.

Orelle

based on the answer above, the only option for lazy loading would be to create a view. – Mcclendon