Try this
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
DataTable dt = new DataTable();
dt.Columns.Add("unit", typeof(string));
dt.Columns.Add("value", typeof(int));
dt.Columns.Add("date", typeof(DateTime));
dt.Rows.Add(new object[] { "A",2, DateTime.Parse("01-01-2000")});
dt.Rows.Add(new object[] { "B",3, DateTime.Parse("01-01-2000")});
dt.Rows.Add(new object[] { "A",4, DateTime.Parse("02-01-2000")});
string[] uniqueUnits = dt.AsEnumerable().Select(x => x.Field<string>("unit")).Distinct().ToArray();
DataTable dt1 = new DataTable();
dt1.Columns.Add("date", typeof(DateTime));
foreach (string unit in uniqueUnits)
{
dt1.Columns.Add(unit, typeof(int));
}
var groups = dt.AsEnumerable().GroupBy(x => x.Field<DateTime>("date"));
foreach (var group in groups)
{
DataRow newRow = dt1.Rows.Add();
foreach (DataRow row in group)
{
newRow["date"] = group.Key;
newRow[row.Field<string>("unit")] = row.Field<int>("value");
}
}
}
}
}
solved Datatable group and pivot