Code is executing without any error, but database is not updating

'generating transaction ID
 Dim dateAndTime As Date = Now
 Dim tra_id As Long = Format(dateAndTime, "ddHHmm")

 'inserting into database
 db_connect.Open()
 Dim indate As Date = System.DateTime.Today
 Dim R_index As Integer
 For R_index = 0 To dataGrid_incoming.Rows.Count - 2


     Dim tempLot As String = dataGrid_incoming.Rows(R_index).Cells(1).Value.ToString
     Dim temptot As String = dataGrid_incoming.Rows(R_index).Cells(2).Value.ToString
     Dim tempqty As Integer = dataGrid_incoming.Rows(R_index).Cells(3).Value
     Dim tempdet As String = dataGrid_incoming.Rows(R_index).Cells(4).Value.ToString

     Dim cmd As SqlClient.SqlCommand = db_connect.CreateCommand()
     cmd.CommandText = "Insert into item (tra_id, lot_no, totul ,qty , tra_status ) Values(" & tra_id & ", '" & tempLot & "', '" & temptot & "'," & tempqty & ", 'In_coming')"
     ' cmd.CommandText = "Insert into item (tra_id, lot_no, totul ,qty , tra_status ) Values(" & tra_id & ", '" & dataGrid_incoming.Rows(R_index).Cells(1).Value.ToString & "', '" & dataGrid_incoming.Rows(R_index).Cells(2).Value.ToString & "'," & dataGrid_incoming.Rows(R_index).Cells(3).Value & ", 'In_coming')"

     Dim cmd2 As SqlClient.SqlCommand = db_connect.CreateCommand()
     cmd2.CommandText = "Insert into item_in (cus_id , tra_id , in_date ,in_detail) Values(" & cs_id & ", " & tra_id & ", " & indate & ", '" & tempdet & "')"
     'cmd2.CommandText = "Insert into item_in (cus_id , tra_id , in_date ,in_detail) Values(" & cs_id & ", " & tra_id & ", " & indate & ", '" & dataGrid_incoming.Rows(R_index).Cells(4).Value.ToString & "')"

 Next

 db_connect.Close()
 dataGrid_incoming.Rows.Clear()