Esempio del metodo Clone (VBScript)

  • Articolo

In questo esempio si usa il metodo Clone per creare copie di un oggetto Recordset e quindi consente all'utente di posizionare in modo indipendente il puntatore a record di ogni copia.

Usare l'esempio seguente in una pagina ASP (Active Server Page). In questo esempio si usa il database Northwind distribuito con Microsoft Access. Tagliare e incollare il codice seguente nel Blocco note o in un altro editor di testo e salvarlo come CloneVBS.asp. È possibile visualizzare il risultato in qualsiasi browser client.

Per eseguire l'esempio, modificare la riga RsCustomerList.Source = "Customers" in RsCustomerList.Source = "Products" per conteggiare una tabella di dimensioni maggiori.

<!-- BeginCloneVBS -->  
<% Language = VBScript %>  
<%' use this meta tag instead of adovbs.inc%>  
<!--METADATA TYPE="typelib" uuid="00000205-0000-0010-8000-00AA006D2EA4" -->  
<HTML>  
<HEAD>  
<TITLE>ADO Clone Method</TITLE>  
</HEAD>  
  
<BODY>  
  
<H1 align="center">ADO Clone Method</H1>  
<HR>  
<% ' to integrate/test this code replace the   
   ' Data Source value in the Connection string%>  
<%   
    ' connection and recordset variables  
    Dim Cnxn, strCnxn  
    Dim rsCustomers, strSQLCustomers  
    Dim rsFirst, rsLast, rsCount  
    Dim rsClone  
    Dim CloneFirst, CloneLast, CloneCount  
  
    ' open connection  
    Set Cnxn = Server.CreateObject("ADODB.Connection")  
    strCnxn = "Provider='sqloledb';Data Source=" & _  
            Request.ServerVariables("SERVER_NAME") & ";" & _  
            "Integrated Security='SSPI';Initial Catalog='Northwind';"  
    Cnxn.Open strCnxn  
  
    ' create and open Recordset using object refs  
    Set rsCustomers = Server.CreateObject("ADODB.Recordset")  
    strSQLCustomers = "Customers"  
  
    rsCustomers.ActiveConnection = Cnxn  
    rsCustomers.CursorLocation = adUseClient  
    rsCustomers.CursorType = adOpenKeyset  
    rsCustomers.LockType = adLockOptimistic  
    rsCustomers.Source = strSQLCustomers  
    rsCustomers.Open  
  
    rsCustomers.MoveFirst  
    rsCount = rsCustomers.RecordCount  
    rsFirst = rsCustomers("CompanyName")  
    rsCustomers.MoveLast  
    rsLast = rsCustomers("CompanyName")  
  
    ' create clone  
    Set rsClone = rsCustomers.Clone  
    rsClone.MoveFirst  
    CloneCount = rsClone.RecordCount  
    CloneFirst = rsClone("CompanyName")  
    rsClone.MoveLast  
    CloneLast = rsClone("CompanyName")  
%>  
  
<!-- Display Results -->  
<H3>There Are <%=rsCount%> Records in the original recordset</H3>  
<H3>The first record is <%=rsFirst%> and the last record is <%=rsLast%></H3>  
<BR><HR>  
<H3>There Are <%=CloneCount%> Records in the original recordset</H3>  
<H3>The first record is <%=CloneFirst%> and the last record is <%=CloneLast%></H3>  
<BR><HR>  
<H4>Location of OLEDB Database</H4>  
  
<%  
    ' Show location of DSN data source  
    Response.Write(Cnxn)  
  
    ' Clean up  
    If rsCustomers.State = adStateOpen then  
       rsCustomers.Close  
    End If  
    If rsClone.State = adStateOpen then  
       rsClone.Close  
    End If  
    If Cnxn.State = adStateOpen then  
       Cnxn.Close  
    End If  
    Set rsCustomers = Nothing  
    Set rsClone = Nothing  
    Set Cnxn = Nothing  
%>  
</BODY>  
</HTML>  
<!-- EndCloneVBS -->

Vedere anche

Metodo Clone (ADO)
Oggetto Recordset (ADO)