DataTable Linq Example

    DataTable CreateTable()
    {
        DataTable dtable = new DataTable();
        DataColumn dc;
        //MId CId FId PId  
        dc = new DataColumn("MId", Type.GetType("System.Int32"));
        dtable.Columns.Add(dc);
        dc = new DataColumn("CId", Type.GetType("System.Int32"));
        dtable.Columns.Add(dc);
        dc = new DataColumn("FId", Type.GetType("System.Int32"));
        dtable.Columns.Add(dc);
        dc = new DataColumn("PId", Type.GetType("System.String"));
        dtable.Columns.Add(dc);
        return dtable;
    }

    void LinqDataTable(HttpResponse Response)
    {
        DataTable dtable  = CreateTable();
        for (int i = 0; i < 30; i++)
        {
            DataRow Dr;
            Dr = dtable.NewRow();
            Dr["MId"] = i;
            Dr["CId"] = i + 1;
            Dr["FId"] = i + 2;
            Dr["PId"] = i%2 ==0? "A":"B";
            dtable.Rows.Add(Dr);
        }
        var query = (from t in dtable.AsEnumerable()
                     //where t.Field<string>("PId") == "A"　　　　　　　　　　
                     orderby t.Field<int>("MId")
                     group t by new
                     {
                         Mid = t.Field<Int32>("MId"),
                         PId = t.Field<string>("PId")
                     } into g
                     //where g.Key.PId == "B"
                     select new
                     {
                         MId = g.Key.Mid,
                         PId = g.Key.PId
                     });

        var AGroup = query.Where((a => a.PId == "A"));
        var BGroup = query.Where((a => a.PId == "B"));
        var sum = query.Sum((a => a.PId));
        foreach (var v in AGroup)
        {
            Response.Write("</br>" + v.PId + "\t" + v.MId);
        }
        foreach (var v in BGroup)
        {
            Response.Write("</br>" + v.PId + "\t" + v.MId);
        }
        Response.End();
    }