Linq query to join two objects and calculate sum

Question

I have two lists of objects that I need to join on Sku and then caluclate the Sum (Qty * Price). I'm not exactly sure how to do this? Here is what I have so far:

List<Order> orders = new List <Order> 
{ 
    new Order() { Sku = "ABC", Qty = 1 },
    new Order() { Sku = "XYZ", Qty = 2}
};

List<Cost> costs = new List <Cost> 
{ 
    new Cost() { Sku = "ABC", Price = 4.50m },
    new Cost() { Sku = "XYZ", Price = 2.25m }
};


var profit = from order in orders
             join cost in costs
             on order.Sku equals cost.Sku
             select Sum(order.Qty * cost.Price)

It doesn't like the last line `select Sum(order.Qty * cost.Price)` — PixelPaul, Mar 02 '17 at 12:56
What if there are not exactly 1:1 `Order` and `Cost` objects? I assume you're going to need some grouping. — Gert Arnold, Mar 02 '17 at 13:17
Possible duplicate of [Sum of items in a collection](http://stackoverflow.com/questions/61870/sum-of-items-in-a-collection) — Andrew, Mar 02 '17 at 13:43

score 5 · Accepted Answer · edited May 23 '17 at 11:46

5

Change your last part as follows:

var profit = (from order in orders
             join cost in costs
             on order.Sku equals cost.Sku
             select (order.Qty * cost.Price)).Sum();

Taken from here: Stackoverflow question that answered how to sum

edited May 23 '17 at 11:46

Community

1
1

answered Mar 02 '17 at 12:59

Ori Nachum

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19

If this solved your issue (I saw in a snippet it worked for me), kindly mark this as answered for future reference. – Ori Nachum Mar 02 '17 at 13:02
1

Thanks for the response, just what I needed. – PixelPaul Mar 02 '17 at 13:07

Linq query to join two objects and calculate sum

1 Answers1