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CacheSize-Eigenschaft (Beispiel) (JScript)

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Gilt für: Access 2013, Office 2013

In diesem Beispiel wird mithilfe der CacheSize-Eigenschaft der Unterschied im Hinblick auf die Leistung für einen Vorgang aufgezeigt, der mit und ohne einen Cache für 30 Datensätze ausgeführt wird. Schneiden Sie den folgenden Code aus, fügen Sie ihn in Editor oder einem anderen Texteditor ein, und speichern Sie ihn unter dem Dateinamen 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 -->