สอบถามวิธีการเขียนโปรแกรมตรวจสอบค่าที่ใส่ในฐานข้อมูล sql server 2008 โดยใช้ vb2010

	Dim intNumRows As Integer
	strSQL = "SELECT COUNT(*) FROM customer WHERE CustomerID = '"& Me.txtCustomerID.Text &"' "		
	objCmd = New SqlCommand(strSQL, objConn)
	intNumRows = objCmd.ExecuteScalar()

	IF intNumRows > 0 Then
		Me.lblStatus.Text = "CustomerID already exist."
	Else	
		' /// Do
	End IF

Private Sub save_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles save.Click
        Dim sav As MsgBoxResult
        Dim sqladd As String
        Dim cm As New SqlCommand
        Conn = New SqlConnection("Data Source=TOSHIBA-PC\SQLEXPRESS;Initial Catalog=rfid2;Integrated Security=True")
        Conn.Open()
        If TextBox1.Text = "" Or TextBox2.Text = "" Or TextBox3.Text = "" Then
            MessageBox.Show("คุณยังกรอกข้อมูลไม่ครบถ้วน")
            Exit Sub
        End If
        sav = MessageBox.Show("คุณต้องการบันทึกข้อมูลหรือไม่?", "rfid", MessageBoxButtons.YesNo, MessageBoxIcon.Question)
        If sav = MsgBoxResult.Yes Then
                sqladd = "INSERT INTO rfidtable(CardSN,Firstname,Surname)"
                sqladd &= "VALUES ( ' " & TextBox1.Text & " ',' " & TextBox2.Text & " ',' " & TextBox3.Text & " ') "
                With cm
                    .CommandType = CommandType.Text
                    .CommandText = sqladd
                    .Connection = Conn
                    .ExecuteNonQuery()
                End With
            End If
            MessageBox.Show("บันทึกข้อมูลเรียบร้อย", "rfid", MessageBoxButtons.OK, MessageBoxIcon.Information)
            TextBox1.Clear()
            TextBox2.Clear()
            TextBox3.Clear()
    End Sub