select more column not in group by using linq in c# - asp.net

Question

cmd = new SqlCommand(" ", con);
da = new SqlDataAdapter(cmd);
DataTable t_eight = new DataTable("t_eight");
da.Fill(t_eight); //databale "t_eight" fill
//linq query
var query3 = (from a in t_eight.AsEnumerable() //t_eigth Databale
group a by new
{ //Group by with condition
IdendityName = a.Field<String>("Idendity Name"),
ContactPersonName = a.Field<String>("Contact Person Name"),
CustomerName = a.Field<String>("Customer Name")
}
into g
select new
{
IdendinyName = g.Key.IdendityName,
ContactPersonName = g.Key.ContactPersonName,
CurtomerName = g.Key.CustomerName,
TotalBook = g.Sum(x => x.Field<Int32>("Total Book Quantity")
+ x.Field<Int32>("Quatan Book Qty")
- x.Field<Int32>("Return Book Quality"))
});
GridView1.DataSource = query3;
GridView1.DataBind();
Datatable contains columns Identity Name, customer Name, customer Contact Name, Total Book Quantity, Return Book Quality, and Quatan Book Qty.
Group by contains three column Identity Name, customer Name, and customer Contact Name
New column in select statement Total Book contains ( total book quant+Quatan Book Qty-Return Book Quality). I want all columns in the gridview but the grid contains Identity Name, customer Name, customer Contact Name, and total book columns
How can I do this?
Dataset table "t_eight"
Gridview missing column Quatan Book and Return Book

Answer 1

Assuming you expect the additional fields to be identical once the rows are grouped, you just need to pick a random row from the group to get the values - the First row should work.
var query3 = (from a in t_eight.AsEnumerable()//t_eigth Databale
group a by new
{//Group by with condition
IdendityName = a.Field<String>("Idendity Name"),
ContactPersonName = a.Field<String>("Contact Person Name"),
CustomerName = a.Field<String>("Customer Name")
}
into g
select new {
g.Key.IdendityName,
g.Key.ContactPersonName,
g.Key.CustomerName,
ReturnBookQuality = g.First().Field<Int32>("Return Book Quality"),
QuatanBookQty = g.First().Field<Int32>("Quatan Book Qty"),
TotalBook = g.Sum(x => x.Field<Int32>("Total Book Quantity")
+ x.Field<Int32>("Quatan Book Qty") - x.Field<Int32>("Return Book Quality"))
}
);
Note: I removed the redundant member names from the anonymous type, I don't see any reason to put them there.

Answer 2

If I understand you correctly, you want to see the totals of three columns besides the calculated TotalBook column. Here's how you can do that:
var query3 = (from a in t_eight.AsEnumerable()
group a by new
{
IdendityName = a.Field<String>("Idendity Name"),
ContactPersonName = a.Field<String>("Contact Person Name"),
CustomerName = a.Field<String>("Customer Name")
}
into g
let tbq = g.Sum(x => x.Field<Int32>("Total Book Quantity"))
let qbq = g.Sum(x => x.Field<Int32>("Quatan Book Qty"))
let rbq = g.Sum(x => x.Field<Int32>("Return Book Quality"))
select new
{
IdendinyName = g.Key.IdendityName,
ContactPersonName = g.Key.ContactPersonName,
CurtomerName = g.Key.CustomerName,
TotalBookQuantity = tbq,
QuatanBookQuantity = qbq,
ReturnBookQuantity = rbq,
TotalBook = tbq + qbq - rbq
});
The three let statements collect the individual sums per grouping, after which you can use the variables tbq etc. multiple times.