Mutilevel include in C# Linq

问题

I want to have MULTILEVEL include in my linq statment, something like

var a = departments.include(u=>u.Customers)
                   .include(u=>u.Customers.Include(u=>u.Orders);

How should i do that?

Thanks

回答1:

You of course can use lambda expression but you must use special format:

var a = departments.Include(d => d.Customers.Select(c => c.Orders));

回答2:

This should do the trick:

departments.Include("Customers.Orders");

Obviously you can't use a lambda expression anymore.

cf. documentation here: http://msdn.microsoft.com/en-us/library/bb738708.aspx

回答3:

[Jeroenh was quicker, but lambda is ok i think...]

Shouldnt be a problem. For entity framework without proxies we use:

var a=departments.Include("Customers.Orders").Single(dept => dept.Customers.Id == id);

/Victor

回答4:

You could specify which nested objects to be retrieved when the query is being executed by using the LoadWith method.

来源：https://stackoverflow.com/questions/8742581/mutilevel-include-in-c-sharp-linq