A Complete C# Example LINQ DataTable Query - Group Aggregation

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Xml;

using System.IO;

using System.Data;

using System.Data.OleDb;

namespace ConsoleApplication2

{

    class Program

    {

        static void Main(string[] args)

        {

            DataTable table = new DataTable();

            table.Columns.Add("Id", typeof(int));

            table.Columns.Add("Value", typeof(decimal));

            table.Rows.Add(123, 4.0M);

            table.Rows.Add(123, 5.0M);

            table.Rows.Add(234, 1.0M);

            table.Rows.Add(345, 2.0M);

            table.Rows.Add(345, 3.0M);

           

            var query = from row in table.AsEnumerable()

                        group row by new

                        {

                            Id = row.Field<Int32>("Id")

                           

                        } into grp

                      

                        select new

                        {

                            Key = grp.Key,

                           

                          

                            SumValue = grp.Sum(r => r.Field<decimal>("Value")),

                           

                        };

            foreach (var grp in query)

            {

                Console.WriteLine("{0}\t{1}", grp.Key, grp.SumValue);

            }

            Console.ReadLine();

        }

    }

}