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CacheSize-Eigenschaft (Beispiel) (JScript)

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In diesem Beispiel wird die CacheSize-Eigenschaft verwendet, um den Leistungsunterschied für einen Vorgang anzuzeigen, der mit und ohne einen Cache mit 30 Datensätzen ausgeführt wird. Schneiden Sie den folgenden Code aus, fügen Sie ihn in Editor oder einem anderen Texteditor ein, und speichern Sie ihn als CacheSizeJS.asp.

<!-- BeginCacheSizeJS -->  
<%@ Language="JScript" %>  
<%// use this meta tag instead of adojavas.inc%>  
<!--METADATA TYPE="typelib" uuid="00000205-0000-0010-8000-00AA006D2EA4" -->  
  
<HTML>  
<HEAD>  
<title>CacheSize Property Example (JScript)</title>  
<style>  
<!--  
body {  
   font-family: 'Verdana','Arial','Helvetica',sans-serif;  
   BACKGROUND-COLOR:white;  
   COLOR:black;  
    }  
.thead2 {  
   background-color: #800000;   
   font-family: 'Verdana','Arial','Helvetica',sans-serif;   
   font-size: x-small;  
   color: white;  
   }  
.tbody {   
   text-align: center;  
   background-color: #f7efde;  
   font-family: 'Verdana','Arial','Helvetica',sans-serif;   
   font-size: x-small;  
    }  
-->  
</style>  
</HEAD>  
<BODY>  
<h1>CacheSize Property Example (JScript)</h1>  
<%  
    // connection and recordset variables  
    var Cnxn = Server.CreateObject("ADODB.Connection")  
    var strCnxn = "Provider='sqloledb';Data Source=" + Request.ServerVariables("SERVER_NAME") + ";" +  
            "Initial Catalog='Northwind';Integrated Security='SSPI';";  
    var rsCustomer = Server.CreateObject("ADODB.Recordset");  
    // caching variables  
    var Now = new Date();  
    var Start = Now.getTime();  
    var End, Cache, NoCache  
  
    try  
    {  
        // open connection  
        Cnxn.Open(strCnxn)  
  
        // open a recordset on the Employee table using client-side cursor  
        rsCustomer.CursorLocation = adUseClient;  
        rsCustomer.Open("Customers", strCnxn);  
  
        // loop through the recordset 20 times  
        for (var i=1; i<=20; i++)  
        {  
            rsCustomer.MoveFirst();  
            while (!rsCustomer.EOF)  
            {  
                // do something with the record  
                var strTemp = new String(rsCustomer("CompanyName"));  
                rsCustomer.MoveNext();  
            }  
        }  
  
        Now = new Date();  
        End = Now.getTime();  
        NoCache = End - Start;  
  
        // cache records in groups of 30  
        rsCustomer.MoveFirst();  
        rsCustomer.CacheSize = 30;  
  
        Now = new Date();  
        Start = Now.getTime();  
  
        // loop through the recordset 20 times  
        for (var i=1; i<=20; i++)  
        {  
            rsCustomer.MoveFirst();  
            while (!rsCustomer.EOF)  
            {  
                // do something with the record  
                var strTemp = new String(rsCustomer("CompanyName"));  
                rsCustomer.MoveNext();  
            }  
        }  
  
        Now = new Date();  
        End = Now.getTime();  
        var Cache = End - Start;  
    }  
    catch (e)  
    {  
        Response.Write(e.message);  
    }  
    finally  
    {  
        // clean up  
        if (rsCustomer.State == adStateOpen)  
            rsCustomer.Close;  
        if (Cnxn.State == adStateOpen)  
            Cnxn.Close;  
        rsCustomer = null;  
        Cnxn = null;  
    }  
%>  
  
    <table border="2">  
        <tr class="thead2">  
            <th>No Cache</th>  
            <th>30 Record Cache</th>  
        </tr>  
        <tr class="tbody">  
            <td><%=NoCache%></td>  
            <td><%=Cache%></td>  
        </tr>  
    </table>  
  
</BODY>  
</HTML>  
<!-- EndCacheSizeJS -->

Siehe auch

CacheSize-Eigenschaft (ADO)
Recordset-Objekt (ADO)