จะดึงข้อมูลใน database มาพักไว้ใน dataset แล้วค่อยเรียกใช้

 Sub date_select()
        If datetime_chack = "1" Then
            sql = " SELECT itemcode, price from Invcostlastprice7_00_011 where itemcode = '" & TxtID.Text & "'"
        ElseIf datetime_chack = "2" Then
            sql = " SELECT itemcode, price from Invcostlastprice7_01_011 where itemcode = '" & TxtID.Text & "'"
        ElseIf datetime_chack = "3" Then
            sql = " SELECT itemcode, price from Invcostlastprice7_02_011 where itemcode = '" & TxtID.Text & "'"
        ElseIf datetime_chack = "4" Then
            sql = " SELECT itemcode, price from Invcostlastprice7_03_011 where itemcode = '" & TxtID.Text & "'"
        ElseIf datetime_chack = "5" Then
            sql = " SELECT itemcode, price from Invcostlastprice7_04_011 where itemcode = '" & TxtID.Text & "'"
        ElseIf datetime_chack = "6" Then
            sql = " SELECT itemcode, price from Invcostlastprice7_05_011 where itemcode = '" & TxtID.Text & "'"
        ElseIf datetime_chack = "7" Then
            sql = " SELECT itemcode, price from Invcostlastprice7_06_011 where itemcode = '" & TxtID.Text & "'"
        ElseIf datetime_chack = "8" Then
            sql = " SELECT itemcode, price from Invcostlastprice7_07_011 where itemcode = '" & TxtID.Text & "'"
        ElseIf datetime_chack = "9" Then
            sql = " SELECT itemcode, price from Invcostlastprice7_08_011 where itemcode = '" & TxtID.Text & "'"
        ElseIf datetime_chack = "10" Then
            sql = " SELECT itemcode, price from Invcostlastprice7_09_011 where itemcode = '" & TxtID.Text & "'"
        ElseIf datetime_chack = "11" Then
            sql = " SELECT itemcode, price from Invcostlastprice7_10_011 where itemcode = '" & TxtID.Text & "'"
        ElseIf datetime_chack = "12" Then
            sql = " SELECT itemcode, price from Invcostlastprice7_11_011 where itemcode = '" & TxtID.Text & "'"
        Else
            MessageBox.Show("ไม่พบข้อมูลที่ต้องการ", "การแจ้งเตือน", MessageBoxButtons.OK, MessageBoxIcon.Warning)
            Exit Sub
        End If

        Dim str As String = ""
        da = New SqlDataAdapter(sql, cn)
        dtsearch = New DataTable
        da.Fill(dtsearch)
        If dtsearch.Rows.Count > 0 Then
            If TxtNum.Text = "" Then
                ' MessageBox.Show("กรุณารับุจำนวน", "การแจ้งเตือน", MessageBoxButtons.OK, MessageBoxIcon.Warning)
                Exit Sub
            End If
            str = dtsearch.Rows(0).Item("price")
            Txtcost.Text = str.Trim
            Txtcost.Text = Math.Round(Val(Txtcost.Text), 2)
            Txtcost.Text = String.Format("{0:0.00}", Double.Parse(Txtcost.Text))
            Txtvalue.Text = str * Convert.ToDouble(TxtNum.Text)
            Txtvalue.Text = Math.Round(Val(Txtvalue.Text), 2)
            Txtvalue.Text = String.Format("{0:0.00}", Double.Parse(Txtvalue.Text))
          
        Exit Sub
        End If
    End Sub