Sum and group linq

Question

I have tried to sort this out myself but I am having to do it in VB which confuddles me even more. basically I have a lit of objects

List<Pax> paxes;

one of the Pax properties is Voucher, which in turn has some properties such as ID, and Price

what I want to do is select out of a list of Pax, a list of Vouchers and their cumulative prices

so from 
Pax1 - Voucher{ VoucherDesc = 10 percent off, VoucherCode = 10-OFF, Price = £150}
Pax2 - Voucher{ VoucherDesc = 10 percent off, VoucherCode = 10-OFF, Price = £120}
Pax3 - Voucher{ VoucherDesc = Buy one get one free, VoucherCode = BOGOF, Price = £300}

to 
{10 percent off, 10-OFF, £270 }
{Buy one get one free, BOGO, £300 }

I am sure this is possible with a bit of linq and grouping, but I am completely stumped

presume it is along the lines of

dim newlist = from p in paxes group p by p.VoucherCode into g _ 
                select new With {g. ..} 

yes this has to end up in VB but as I find that rather painful, figured I would make more sense of it in C# however, as the VB syntax is pure evil, if someone could post both, I might finally be able to make sense of what its doing. as the code converter doesn't seem to play nicely with extended linq queries.

any help much appreciated

Answer 1

thanks for the replies

managed to convert that to vb thus

Dim q = From v In paxes.Select(Function(p) p.Voucher).Where(Function(v) v IsNot Nothing) _
        Group v By v.OptionID, v.VoucherCode, v.Description Into Group _
        Select OptionID, VoucherCode, Description, TotalDiscount = Group.Sum(Function(v) v.Price)

fields are named a little different but it works fine helped by lazyb's post and this link: http://msdn.microsoft.com/en-us/vstudio/bb688088.aspx

Answer 2

Assume price is a decimal or double (not string):

var query = from v in paxes.Select(p => p.Voucher)
            group v by new {v.VoucherDesc, v.VoucherCode } into g
            select new { 
                Desc = g.Key.VoucherDesc,
                Code = g.Key.VoucherCode, 
                Total = g.Sum(x => x.Price)
            }; 

Update: you question was initially tagged with C#, thus this is a C# solution. Hope you can translate it to VB. If price is string, then just add parsing of value. E.g.

Total = g.Sum(x => Double.Parse(x.Price.Replace("£", ""))

---