Unable to fill dataset with oracledataadpter

Question

i am facing very strange problem , I am using the following piece of code but ds is not filled some times there is data in the ds but not always, I have change the connection pool and also restart the iis but no luck at all , I am not able to find where the problem is please help me out. I am running the same query in the TOAD and its giving result , I have also commit the transaction for if any thing in inconsistent.

 Dim command As New OracleCommand
        Dim ds As New DataSet
        Try
            Using connection As New OracleConnection
(ConfigurationManager.ConnectionStrings("CA").ConnectionString.ToString())
                connection.Open()
                command.Connection = connection
                command.CommandText = "SELECT w.portfolio, w.appl_group,
tm.trng_title, p.tt_program_title," & _
                                     " p.created_date,
p.tt_target_completion_date, p.tt_prog_status," & _
                                     " w.emp_id, w.first_name || ' ' ||
w.last_name, ('Y') training_done_flag," & _
                                     "         t.actual_completion_date,
p.created_by, w.people_manager, " & _
                                     "        w.project_manager, w.flag" &
_
                                    " FROM tt_training_done_records t," & _
                                     "    wsr_employee w, " & _
                                     "   tt_training_master  tm, " & _
                                    "  tt_newprogram p" & _
                                    " WHERE(w.emp_id = t.employee_id)" & _
                                    " AND t.training_info_id = tm.trng_id"
& _
                                    " AND p.tt_program_id(+) =
t.program_id" & _
                                    " AND tm.trng_id IN ( 'TT_009' ) " & _
                                    " AND t.actual_completion_date BETWEEN
TO_DATE('11-Mar-2009')  AND TO_DATE('11-Mar-2013') " & _
                                    " "

                Dim adpt As New OracleDataAdapter(command)
                adpt.AcceptChangesDuringFill = False
                adpt.Fill(ds)
                connection.Close()
            End Using

Answer 1

Don't rely on the default behavior of casting a string into a date. Either use a date literal or provide the format string argument. This introduces a dependency on NLS environment settings your .NET code should not depend upon.

Instead of TO_DATE('11-Mar-2013')

Try date '2013-03-11' or TO_DATE('11-Mar-2013'), 'DD-Mon-YYYY')