ASP提高数据显示效率-缓存探幽
点击次数：33 次 发布日期：2008-11-22 11:31:10 作者：源代码网
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以下是引用片段： Function DisplayRecords() "这个函数原来给一个变量temp付上记录的值 Dim sql, conn, rs "符合条件的sql语句 sql = "SELECT id, [szd_f], [szd_t] FROM admin" "打开数据库连接 Set conn = Server.CreateObject("ADODB.Connection") conn.Open "DRIVER={Microsoft Access Driver (*.mdb)}; DBQ="&Server.MapPath("db.mdb") Set rs = Server.CreateObject("ADODB.Recordset") rs.Open sql, conn, 1, 3 "当符合sq语句l的数据没有显示完毕时 If Not rs.EOF Then "给temp变量赋值 Dim temp temp = "<table width=""90%"" align=""center""" temp = temp & " border=""1"" bordercolor=""silver""" temp = temp & " cellspacing=""2"" cellpadding=""0"">" temp = temp & "<tr bgcolor=""#CCDDEE""><td width=""5%""" temp = temp & ">ID</td><td>操作</td>" temp = temp & "<td>数值</td></tr>" While Not rs.EOF temp = temp & "<tr><td bgcolor=""#CCDDEE"">" temp = temp & rs("ID") & "</td><td>" & rs("szd_f") temp = temp & "</td><td>" & rs("szd_t") temp = temp & "</td></tr>" rs.MoveNext Wend temp = temp & "</table>" "temp赋值完毕,把它再返回给函数 DisplayRecords = temp Else DisplayRecords = "Data Not Available." End If "释放内存 rs.Close conn.Close Set rs = Nothing Set conn = Nothing End Function ok,上面的函数改造完毕,调用的时候就是DisplayRecords. 下面是application大显身手了: "该函数是写入缓存 Function DisplayCachedRecords(Secs) Dim retVal, datVal, temp1 "Secs是每次要刷新数据的时间, retVal是数据,datVal是剩余时间 retVal = Application("cache_demo") "取得appliction的值 datVal = Application("cache_demo_date") "取得appliction的值 "判断datVal 的值,也就是要计算时间过去了没 If datVal = "" Then "如果是空,datVal值为当前时间按秒加上secs定义的时间 datVal = DateAdd("s",Secs,Now) End If "temp1是判断当前时间和datVal的秒差 temp1 = DateDiff("s", Now, datVal) "如果retVal已经是上面函数的返回值且时间大于0 If temp1 > 0 And retVal <> "" Then "本函数返回记录数 DisplayCachedRecords = retVal Response.Write "<b><font color=""green"">利用缓存读取数据" Response.Write " ... (" & temp1 & " 秒剩余)</font></b>" Response.Write "<br><br>" Else "retVal 是空的话,就赋予DisplayRecords的值给变量temp2 Dim temp2 temp2 = DisplayRecords() "保存到Application.------------------>重点 Application.Lock Application("cache_demo") = temp2 Application("cache_demo_date") = DateAdd("s",Secs,Now) Application.UnLock DisplayCachedRecords = temp2 " 这里随便写上了记录的缓存的过去时间,相对总秒数倒差 : Response.Write "<b><font color=""red"">刷新缓存显示 ..." Response.Write "</font></b><br><br>" End If End Function %> 说明完毕. 以下为完整无注释代码 调用方法:<%=DisplayCachedRecords(20)%> 写在后面的话:如果你感觉你的服务器内存不够大的话,不要大量使用缓存. 源代码网供稿. |
