How do I transfer this code from SQL to Linq in C sharp?

I have really tried hard to get it working but I cant find the correct way to implement it in c sharp by using Linq.


SQL-Code:

SELECT Aktie.Papirnavn, Portfolio.Antal, Dagskurs.Dagskurs, Sum([Antal]*[Dagskurs]) AS Værdi
FROM (Aktie INNER JOIN Portfolio ON Aktie.Fondskode = Portfolio.Fondskode) INNER JOIN Dagskurs ON Portfolio.Fondskode = Dagskurs.Fondskode
GROUP BY Aktie.Papirnavn, Portfolio.Antal, Dagskurs.Dagskurs, Portfolio.PortfID
HAVING (((Portfolio.PortfID)="Forsigtig"));

I tried to implement some but when I try to "translate" from the pieces I read on different sites I just get tons of errors I cant understand. I got this working in a buttonclick:


            DataClasses1DataContext xxx = new DataClasses1DataContext();
            var pa = from Aktie in xxx.Akties
            join Portfolio in xxx.Portfolios on Aktie.Fondskode equals Portfolio.Fondskode
            select new {Aktie.Papirnavn, Portfolio.Antal};

            dataGridView1.DataSource = pa;



But when I try to get it more advanced i get stuck.