ASP中Cache技术的应用(2)

　　Dim HTMLStream
　　Dim IsExpires
　　IsExpires = CacheExpires
　　Function CacheExpires
　　Dim strLastUpdate
　　Dim result strLastUpdate = Application("LastUpdate")
　　If (strLastUpdate = "") Or (CACHE_DEFAULT_INTERVAL < DateDiff("s", strLastUpdate, Now)) Then
　　result = true
　　SetLastUpdateTime
　　Else
　　result = false
　　End If
　　CacheExpires = result
　　End Function

Sub SetLastUpdateTime
　　Application.Lock
　　Application("LastUpdate") = CStr(now())
　　Application.UnLock
　　End Sub

　　Sub GetHTMLStream
　　If IsExpires Then
　　UpdateHTMLStream
　　End If
　　HTMLStream=Application("CACHE_HTMLStream")
　　End Sub

　　Sub UpdateHTMLStream
　　dim d
　　d = FetchHTMLStream
　　Application.Lock
　　Application("CACHE_HTMLStream") = d
　　Application.UnLock
　　End Sub

　　Function FetchHTMLStream
　　Dim rs ,strSQL, strHTML
　　Set rs = CreateObject("ADODB.Recordset")
　　strSQL = "select categoryID , categoryname from categories"
　　rs.Open strSQL, strConn,adOpenForwardOnly,adLockReadOnly
　　strHTML = strHTML & "<select name=""slt_search"">"
　　while (not rs.EOF)
　　strHTML = strHTML & "<option>"
　　strHTML = strHTML & rs.Fields("categoryname")
　　strHTML = strHTML & "</option>" rs.MoveNext
　　wend
　　strHTML = strHTML & "</select>"
　　rs.Close
　　Set rs = Nothing
　　FetchHTMLStream = strHTML
　　End Function
　　%>

 

　　ASP：conn.asp

<!--METADATA NAME="Microsoft ActiveX Data Objects 2.5 Library" TYPE="TypeLib" UUID="{00000205-0000-0010-8000-00AA006D2EA4}"-->
　　<%
　　dim strConn
　　strConn = "Provider=SQLOLEDB.1;Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=Northwind"
　　%>