Question

I want to do a group join with the following three tables using linq extension methods

Custumer
Order
OrderShippingInfo

Custumer can have many Orders and each order can have only one OrderShippingInfo.

So my goal is do a group join of these 3 tables and return a anonymous object that has one Customer and an array of {Order, OrderShippinfo}.

I know how to do a groupjoin between customer and order but I don’t know how to add the OrderShippInfo in the collection

     Customer.GroupJoin(Order, c=>c.customerID, o=>o.CustomerID, (c,o)=> new {c,o})

Thanks a lot

Answer 1

How about that:

 Customer.GroupJoin(Order.Join(OrderShippinInfo,
                               o=>o.OrderID,
                               s=>s.OrderID,
                               (o, s) => new { Order = o, ShippingInfo = s}),
                    c=>c.customerID,
                    oi=>oi.Order.CustomerID,
                    (c,oi)=> new {c,oi})