Access 2000 數據庫 80 萬記錄通用快速分頁類

作者:蕭月痕(xiaoyuehen)
地址:http://blog.csdn.net/xiaoyuehen/archive/2005/01/17/257202.aspx
轉貼請包含相關信息, 謝謝.

主要思路: 用一條語句統計(Count)出記錄數(而不在查詢時獲得 RecordCount 屬性), 緩存在 Cookies 中, 跳轉時就不用再次統計, 分頁跳轉鏈接也由此來, 使用 ADO 的 AbsolutePage 屬性設置當前頁面, 返回intPageSize 條記錄. 為方便調用而寫成類, 代碼主要地方已有說明

硬件環境: AMD Athlon XP 2600+, 256 DDR
軟件環境: MS Windows 2000 Advanced Server + IIS 5.0 + Aclearcase/" target="_blank" >ccess 2000 + IE 6.0
測試結果: 初次運行在 250(首頁) - 400(末頁)毫秒, (記錄數緩存后)在頁面間跳轉穩定在 47 毫秒以下.第1頁跳到最后一頁不多于 350 毫秒

適用范圍: 用于普通分頁. 不適用于有較復雜的查詢時: 如條件為"[Title] Like @#%最愛%@#", 查詢的時間大大增加, 就算 Title 字段作了索引也沒用. :(

<%@LANGUAGE = "VBScript" CODEPAGE="936"%>
<%Option Explicit%>
<%
Dim intDateStart
intDateStart = Timer()
Rem ## 打開數據庫連接
Rem #################################################################
function f__OpenConn()
Dim strDbPath
Dim connstr
strDbPath = "../db/test.mdb"
connstr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source="
connstr = connstr & Server.MapPath(strDbPath)
Set conn = Server.CreateObject("Adodb.Connection")
conn.open connstr
End function
Rem #################################################################

Rem ## 關閉數據庫連接
Rem #################################################################
function f__CloseConn()
If IsObject(conn) Then
conn.close
End If
Set conn = nothing
End function
Rem #################################################################
Rem 獲得執行時間
Rem #################################################################
function getTimeOver(iflag)
Dim tTimeOver
If iflag = 1 Then
tTimeOver = FormatNumber(Timer() - intDateStart, 6, true)
getTimeOver = " 執行時間: " & tTimeOver & " 秒"
Else
tTimeOver = FormatNumber((Timer() - intDateStart) * 1000, 3, true)
getTimeOver = " 執行時間: " & tTimeOver & " 毫秒"
End If
End function
Rem #################################################################
Class Cls_PageView
Private sbooInitState
Private sstrCookiesName
Private sstrPageUrl
Private sstrPageVar
Private sstrTableName
Private sstrFieldsList
Private sstrCondiction
Private sstrOrderList
Private sstrPrimaryKey
Private sintRefresh

Private sintRecordCount
Private sintPageSize
Private sintPageNow
Private sintPageMax

Private sobjConn

Private sstrPageInfo

Private Sub Class_Initialize
Call ClearVars()
End Sub

Private Sub class_terminate()
Set sobjConn = nothing
End Sub

Public Sub ClearVars()
sbooInitState = False
sstrCookiesName = ""
sstrPageUrl = ""
sstrPageVar = "page"
sstrTableName = ""
sstrFieldsList = ""
sstrCondiction = ""
sstrOrderList = ""
sstrPrimaryKey = ""
sintRefresh = 0

sintRecordCount = 0
sintPageSize = 0
sintPageNow = 0
sintPageMax = 0
End Sub

Rem ## 保存記錄數的 Cookies 變量
Public Property Let strCookiesName(Value)
sstrCookiesName = Value
End Property

Rem ## 轉向地址
Public Property Let strPageUrl(Value)
sstrPageUrl = Value
End Property

Rem ## 表名
Public Property Let strTableName(Value)
sstrTableName = Value
End Property

Rem ## 字段列表
Public Property Let strFieldsList(Value)
sstrFieldsList = Value
End Property

Rem ## 查詢條件
Public Property Let strCondiction(Value)
If Value <> "" Then
sstrCondiction = " WHERE " & Value
Else
sstrCondiction = ""
End If
End Property

Rem ## 排序字段, 如: [ID] ASC, [CreateDateTime] DESC
Public Property Let strOrderList(Value)
If Value <> "" Then
sstrOrderList = " ORDER BY " & Value
Else
sstrOrderList = ""
End If
End Property

Rem ## 用于統計記錄數的字段
Public Property Let strPrimaryKey(Value)
sstrPrimaryKey = Value
End Property

Rem ## 每頁顯示的記錄條數
Public Property Let intPageSize(Value)
sintPageSize = toNum(Value, 20)
End Property

Rem ## 數據庫連接對象
Public Property Let objConn(Value)
Set sobjConn = Value
End Property

Rem ## 當前頁
Public Property Let intPageNow(Value)
sintPageNow = toNum(Value, 1)
End Property

Rem ## 頁面參數
Public Property Let strPageVar(Value)
sstrPageVar = Value
End Property

Rem ## 是否刷新. 1 為刷新, 其他值則不刷新
Public Property Let intRefresh(Value)
sintRefresh = toNum(Value, 0)
End Property

Rem ## 獲得當前頁
Public Property Get intPageNow()
intPageNow = singPageNow
End Property

Rem ## 分頁信息
Public Property Get strPageInfo()
strPageInfo = sstrPageInfo
End Property

Rem ## 取得記錄集, 二維數組或字串, 在進行循環輸出時必須用 IsArray() 判斷
Public Property Get arrRecordInfo()
If Not sbooInitState Then
Exit Property
End If

Dim rs, sql
sql = "SELECT " & sstrFieldsList & _
" FROM " & sstrTableName & _
sstrCondiction & _
sstrOrderList

Set rs = Server.CreateObject("Adodb.RecordSet")
rs.open sql, sobjConn, 1, 1
If Not(rs.eof or rs.bof) Then
rs.PageSize = sintPageSize
rs.AbsolutePage = sintPageNow
If Not(rs.eof or rs.bof) Then
arrRecordInfo = rs.getrows(sintPageSize)
Else
arrRecordInfo = ""
End If
Else
arrRecordInfo = ""
End If
rs.close
Set rs = nothing
End Property

Rem ## 初始化記錄數
Private Sub InitRecordCount()
sintRecordCount = 0
If Not(sbooInitState) Then Exit Sub
Dim sintTmp
sintTmp = toNum(request.Cookies("_xp_" & sstrCookiesName), -1)
If ((sintTmp < 0) Or (sintRefresh = 1))Then
Dim sql, rs
sql = "SELECT COUNT(" & sstrPrimaryKey & ")" & _
" FROM " & sstrTableName & _
sstrCondiction
Set rs = sobjConn.execute(sql)
If rs.eof or rs.bof Then
sintTmp = 0
Else
sintTmp = rs(0)
End If
sintRecordCount = sintTmp

response.Cookies("_xp_" & sstrCookiesName) = sintTmp
Else
sintRecordCount = sintTmp
End If
End Sub

Rem ## 初始化分頁信息
Private Sub InitPageInfo()
sstrPageInfo = ""
If Not(sbooInitState) Then Exit Sub

Dim surl
surl = sstrPageUrl
If Instr(1, surl, "?", 1) > 0 Then
surl = surl & "&" & sstrPageVar & "="
Else
surl = surl & "?" & sstrPageVar & "="
End If

If sintPageNow <= 0 Then sintPageNow = 1
If sintRecordCount mod sintPageSize = 0 Then
sintPageMax = sintRecordCount \ sintPageSize
Else
sintPageMax = sintRecordCount \ sintPageSize + 1
End If
If sintPageNow > sintPageMax Then sintPageNow = sintPageMax

If sintPageNow <= 1 then
sstrPageInfo = "首頁 上一頁"
Else
sstrPageInfo = sstrPageInfo & " <a href=""" & surl & "1"">首頁</a>"
sstrPageInfo = sstrPageInfo & " <a href=""" & surl & (sintPageNow - 1) & """>上一頁</a>"
End If

If sintPageMax - sintPageNow < 1 then
sstrPageInfo = sstrPageInfo & " 下一頁 末頁 "
Else
sstrPageInfo = sstrPageInfo & " <a href=""" & surl & (sintPageNow + 1) & """>下一頁</a> "
sstrPageInfo = sstrPageInfo & " <a href=""" & surl & sintPageMax & """>末頁</a> "
End If

sstrPageInfo = sstrPageInfo & " 頁次：<strong><font color=""#990000"">" & sintPageNow & "</font> / " & sintPageMax & " </strong>"
sstrPageInfo = sstrPageInfo & " 共 <strong>" & sintRecordCount & "</strong> 條記錄 <strong>" & sintPageSize & "</strong> 條/頁 "
End Sub

Rem ## 長整數轉換
Private function toNum(s, Default)
s = s & ""
If s <> "" And IsNumeric(s) Then
toNum = CLng(s)
Else
toNum = Default
End If
End function

Rem ## 類初始化
Public Sub InitClass()
sbooInitState = True
If Not(IsObject(sobjConn)) Then sbooInitState = False
Call InitRecordCount()
Call InitPageInfo()
End Sub
End Class
Dim strLocalUrl
strLocalUrl = request.ServerVariables("SCRIPT_NAME")

Dim intPageNow
intPageNow = request.QueryString("page")

Dim intPageSize, strPageInfo
intPageSize = 30

Dim arrRecordInfo, i
Dim Conn
f__OpenConn
Dim clsRecordInfo
Set clsRecordInfo = New Cls_PageView

clsRecordInfo.strTableName = "[myTable]"
clsRecordInfo.strPageUrl = strLocalUrl
clsRecordInfo.strFieldsList = "[ID], [Title], [LastTime]"
clsRecordInfo.strCondiction = "[ID] < 10000"
clsRecordInfo.strOrderList = "[ID] ASC"
clsRecordInfo.strPrimaryKey = "[ID]"
clsRecordInfo.intPageSize = 20
clsRecordInfo.intPageNow = intPageNow

clsRecordInfo.strCookiesName = "RecordCount"
clsRecordInfo.strPageVar = "page"

clsRecordInfo.intRefresh = 0
clsRecordInfo.objConn = Conn
clsRecordInfo.InitClass

arrRecordInfo = clsRecordInfo.arrRecordInfo
strPageInfo = clsRecordInfo.strPageInfo
Set clsRecordInfo = nothing
f__CloseConn
%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>分頁測試</title>
<style type="text/css">
<!--
.PageView {
font-size: 12px;
}
.PageView td {
border-right-style: solid;
border-bottom-style: solid;
border-right-color: #E0E0E0;
border-bottom-color: #E0E0E0;
border-right-width: 1px;
border-bottom-width: 1px;
}
.PageView table {
border-left-style: solid;
border-top-style: solid;
border-left-color: #E0E0E0;
border-top-color: #E0E0E0;
border-top-width: 1px;
border-left-width: 1px;
}
tr.Header {
background: #EFF7FF;
font-size: 14px;
font-weight: bold;
line-height: 120%;
text-align: center;
}
-->
</style>
<style type="text/css">
<!--
body {
font-size: 12px;
}
a:link {
color: #993300;
text-decoration: none;
}
a:visited {
color: #003366;
text-decoration: none;
}
a:hover {
color: #0066CC;
text-decoration: underline;
}
a:active {
color: #000000;
text-decoration: none;
}
table {
font-size: 12px;
}
-->
</style>
</head>
<body>
<table width="100%" border="0" cellspacing="0" cellpadding="4">
<tr>
<td>&nbsp;<%= strPageInfo%></td>
</tr>
</table>
<div class="PageView">
<table width="100%" border="0" cellspacing="0" cellpadding="4">
<tr class="Header">
<td>ID</td>
<td>描述</td>
<td>日期</td>
</tr>
<%
If IsArray(arrRecordInfo) Then
For i = 0 to UBound(arrRecordInfo, 2)
%>
<tr>
<td>&nbsp;<%= arrRecordInfo(0, i)%></td>
<td>&nbsp;<%= arrRecordInfo(1, i)%></td>
<td>&nbsp;<%= arrRecordInfo(2, i)%></td>
</tr>
<%
Next
End If
%>
</table>
</div>
<table width="100%" border="0" cellspacing="0" cellpadding="4">
<tr>
<td>&nbsp;<%= strPageInfo%></td>
</tr>
</table>
<table width="100%" border="0" cellspacing="0" cellpadding="4">
<tr>
<td align="center">&nbsp;<%= getTimeOver(1)%></td>
</tr>
</table>
</body>
</html>

這里將所有代碼集中在一起是為了敘述和測試方便, 具體應用你可以將類放在單獨一個文件, 然后多處調用. 請將適當的時候判斷用戶是否進行請求, 更改 intRefresh, 以便告知分頁類是否重新統計記錄數.

原文轉自：http://www.kjueaiud.com