Question

Does anyone know how to write this

var q = from c in customers
        join o in orders on c.Key equals o.Key
        select new {c.Name, o.OrderNumber};

In this syntax style?

var 1= customers.
    .join(???)
    .select(???)

I’ve been googling for a way to do this for days now with now luck. Everyone preferes the first syntax for tutorials, but I find the second much easier to determine order of operation when reading.

Answer 1

The compiler translation process involves using a “transparent identifier” that makes the current customer and order available to the Select method. You can emulate this by making your own:

customers.Join(orders, c => c.Key, o => o.Key, (c, o) => new { c, o })
         .Select(x => new { x.c.Name, x.o.OrderNumber });

Instead, you could just move your Name/OrderNumber projection up into the Join call:

customers.Join(orders, c => c.Key, o => o.Key, (c, o) => new { c.Name, o.OrderNumber });