Am using vb.net.Having dataset contain column name as phone .it contain set of phone number. i want to add 0 to each phone number and store it in another dataset.

my code
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cmd = New OracleCommand("select substr(PHONE,-10)as PHONE from  reports.renewal_contact_t where run_date=to_date('" + TextBox1.Text + "','mm/dd/yyyy') and  EXP_DATE =to_date('" + TextBox2.Text + "','mm/dd/yyyy') and  region not in('TNP')", cn)
                ada = New OracleDataAdapter(cmd)
                ada.Fill(ds, "reports.renewal_contact_t ")
                Dim ds1 As New DataSet
                ds1 = ds.Clone()
                For Each q In ds.Tables(0).Rows
                    phone = z + q("PHONE").ToString
                    For Each q1 In ds1.Tables(0).Rows
                        q1("PHONE") = phone
                    Next
                Next



   my problem is am not getting values in ds1.Please help me to correct it.