VB.NET เขียน insert , edit ข้อมูลเข้า ฐานข้อมูลแล้วเกิดปัญหา error แถมลบข้อมูลบางส่วนหาย

       Try
                With com
                    .CommandType = CommandType.Text
                    .CommandText = "TRUNCATE TABLE BOOKTEMP"
                    .Connection = Conn
                    .Transaction = tr
                    .ExecuteNonQuery()

                    .CommandText = "INSERT INTO BOOKTEMP SELECT * FROM BOOK WHERE COMCODE = '" & tmpComCode & "'"
                    .ExecuteNonQuery()
                End With
                tr.Commit()
            Catch
                MessageBox.Show(Err.Description, "The error", MessageBoxButtons.OK, MessageBoxIcon.Error)
                tr.Rollback()
                Exit Sub
            End Try

Try
         With com
             .CommandType = CommandType.Text
             .CommandText = "TRUNCATE TABLE BOOKTEMP"
             .Connection = Conn
             .ExecuteNonQuery()

             .CommandText = "INSERT INTO BOOKTEMP SELECT * FROM BOOK WHERE COMCODE = '" & tmpComCode & "'"
             .ExecuteNonQuery()
         End With
     Catch
         MessageBox.Show(Err.Description, "The error", MessageBoxButtons.OK, MessageBoxIcon.Error)
         Exit Sub
     End Try