C#

public DataSet ExecuteQuery()
      {
          // construct an empty result database to return

          DataTable table = ds.Tables["Fill_Data"];
          //DataTable table = ds.Tables[0];
          // Presuming the DataTable has a column named Date.
          string expression;
         //expression = "40Percent <" + lblTA.Text.ToString();
         expression = "40Percent = 0.355";

          DataRow[] foundRows;

         // Use the Select method to find all rows matching the filter.
         foundRows = table.Select(expression);

         // Print column 0 of each returned row.
         for (int i = 0; i < foundRows.Length; i++)
         {
             Console.WriteLine(foundRows[i][0]);
         }

         return ds;
      }