How to sum field in already exist Linq result [modified]

[Sam Martini]

I need to sum field depending on 2 tables with 1 to many relations

customer
Id name
1 a
2 b
3 c

Stock
CustID qty
1 10
1 15
2 20

I have somewhere in my project the following

Dim lqcus = From c In db0.customers Where c.id = txt_idcust.Text Select c

I managed to sum by 2 ways

Dim sum1 = (From s In db0.stocks Where s.CustID = txt_idcust.Text Select c.qty).Sum
Dim sum2 = Aggregate s In db0.stocks Where s.CustID = txt_idcust.Text Into sum(s.qty)

But the above 2 will be executed again in the sql server to get the result, but I already have the lqcus which is linq result for the customer and inside the lqcus there is the stock already filtered by the 1 to many relation For example, I can write the following

Dim sum3 = From s In lqcus.stocks Where s.CustID = txt_idcust.Text

But I could not find the syntax to sum the qty Can someone help?

modified on Tuesday, July 19, 2011 6:36 AM

[Sam Martini]

I manage to solve it.

Dim sum3 = Aggregate s In lqcus.stocks Into Sum(s.qty)

Thanks to every one who look at it.