using System;

using System.Collections.Generic;

using System.Data;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace ConsoleApplication2

{

    internal class Program

    {

        private static void Main(string[] args)

        {

            DataTable dt = new DataTable();

            dt.Columns.Add("type", typeof (string));

            dt.Columns.Add("time", typeof (string));

            dt.Columns.Add("action", typeof (string));

            dt.Columns.Add("sum", typeof (string));

            dt.Rows.Add("A", "09:00:00", "举手", "");

            dt.Rows.Add("A", "15:00:00", "扭腰", "");

            dt.Rows.Add("A", "19:00:00", "扭腰", "");

            dt.Rows.Add("B", "08:00:00", "抬脚", "");

            dt.Rows.Add("B", "11:00:00", "举手", "");

            dt.Rows.Add("C", "08:00:00", "扭脖子", "");

            dt.Rows.Add("C", "09:00:00", "提臀", "");

            var query = from t in dt.AsEnumerable()

                group t by new

                {

                    t1 = t.Field<string>("type")

                    //,t2 = t.Field<DateTime>("arrivalTime")多个条件

                }

                into m

                select new

                {

                    time = string.Join("---", m.Select(n => n.Field<string>("time")).ToArray()),

                    type = m.Key.t1,

                    action = string.Join("/", m.Select(n => n.Field<string>("action")).ToArray()),

                    rowcount = m.Count()

                };

              var sss = query.ToList();

        }

    }

}