Dynamically adding the columns in group by clause of linq

Question

I am getting a datatable from service. I am using linq to calculate of sum new columns. I want all the coumns in datatable originally plus the new columns calculated in linq.

Problem is columns in datatable are not fixed. How would I dynamically add the columns in select clause of linq.

Below is code snippet:

DataTable dt = ds.Tables[0];
var orderCtr =
from o in dt.AsEnumerable()
where o.Field<string>(Constants.GENDER_NAME) != "Unknown"
group o by new
{
                    odr_id = o.Field<int>(Constants.ORDER_ID),
                    //NEED TO ADD COLUMNS DYNAMICALLY HERE. MEANS IF THEY ARE IN DATATABLE.
                }
                    into g
                    select new
                    {
                         //NEED TO ADD COLUMNS DYNAMICALLY HERE. MEANS IF THEY ARE IN DATATABLE.
                        odr_id = g.Key.odr_id,
                        ac_gr_imp = g.Sum(r => r.Field<long>(Constants.GENDER_IMPRESSION)),
                        ac_gr_clk = g.Sum(r => r.Field<long>(Constants.GENDER_CLICK)),
                        Ctr = (double)g.Sum(r => r.Field<long>(Constants.GENDER_IMPRESSION)) / g.Sum(r => r.Field<long>(Constants.GENDER_CLICK)),
                    };

Did you find a solution? I have a very similar problem to solve. — Sebastian Widz, Dec 01 '16 at 21:23

score -1 · Answer 1 · answered Sep 17 '13 at 07:01

-1

You might be interested in the Dynamic LINQ library. Dynamic LINQ allows you to specify queries or parts of queries by building strings.

Scott Guthrie described it back in 2008 (http://weblogs.asp.net/scottgu/archive/2008/01/07/dynamic-linq-part-1-using-the-linq-dynamic-query-library.aspx) and there is also a NuGet package of it in case you use .NET 4 (http://www.nuget.org/packages/System.Linq.Dynamic).

answered Sep 17 '13 at 07:01

Roy Dictus

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is there no other way of doing the same? – Ajay Sep 17 '13 at 07:21
Is Dynamic LINQ library only for filtering (where clause) ? How about grouping? – Sebastian Widz Dec 01 '16 at 21:44
Check out http://stackoverflow.com/questions/20329558/how-to-use-groupby-using-dynamic-linq – Roy Dictus Dec 06 '16 at 11:02

Dynamically adding the columns in group by clause of linq

1 Answers1