开发学院 WEB开发 ASP Access2000数据库80万记录通用快速分页类阅读

Access2000数据库80万记录通用快速分页类

　2005-01-18 10:29:54　来源：WEB开发网　　　

核心提示： 主要思路: 用一条语句统计(Count)出记录数(而不在查询时获得 RecordCount 属性), 缓存在 Cookies 中, 跳转时就不用再次统计. 使用 ADO 的 AbsolutePage 属性进行页面跳转即可. 为方便调用而写成类, 代码主要地方已有说明硬件环境: AMD Athlon XP 2600+

　主要思路: 用一条语句统计(Count)出记录数(而不在查询时获得 RecordCount 属性), 缓存在 Cookies 中, 跳转时就不用再次统计. 使用 ADO 的 AbsolutePage 属性进行页面跳转即可. 为方便调用而写成类, 代码主要地方已有说明

硬件环境: AMD Athlon XP 2600+, 256 DDR
软件环境: MS Windows 2000 Advanced Server + IIS 5.0 + access 2000 + IE 6.0
测试结果: 初次运行在 250(首页) - 400(末页)毫秒, (记录数缓存后)在页面间跳转稳定在 47 毫秒以下.第1页跳到最后一页不多于 350 毫秒

适用范围: 用于普通分页. 不适用于有较复杂的查询时: 如条件为"[Title] Like '%最爱%'", 查询的时间大大增加, 就算 Title 字段作了索引也没用. :(
<%@LANGUAGE = "VBScript" CODEPAGE="936"%>
<%Option Explicit%>
<%
Dim intDateStart
intDateStart = Timer()
Rem ## 打开数据库连接
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 ## 关闭数据库连接
Rem #################################################################
function f__CloseConn()
　 If IsObject(conn) Then
　 conn.close
　 End If
　 Set conn = nothing
End function
Rem #################################################################
Rem 获得执行时间
Rem #################################################################
function getTimeOver(iflag)
Dim tTimeOver
If iflag = 1 Then
　 tTimeOver = FormatNumber(Timer() - intDateStart, 6, true)
　 getTimeOver = " 执行时间: " & tTimeOver & " 秒"
Else
　 tTimeOver = FormatNumber((Timer() - intDateStart) * 1000, 3, true)
　 getTimeOver = " 执行时间: " & 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 ## 保存记录数的 Cookies 变量
Public Property Let strCookiesName(Value)
　 sstrCookiesName = Value
End Property

Rem ## 转向地址
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 ## 查询条件
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 ## 用于统计记录数的字段
Public Property Let strPrimaryKey(Value)
　 sstrPrimaryKey = Value
End Property

Rem ## 每页显示的记录条数
Public Property Let intPageSize(Value)
　 sintPageSize = toNum(Value, 20)
End Property

Rem ## 数据库连接对象
Public Property Let objConn(Value)
　 Set sobjConn = Value
End Property

Rem ## 当前页
Public Property Let intPageNow(Value)
　 sintPageNow = toNum(Value, 1)
End Property

Rem ## 页面参数
Public Property Let strPageVar(Value)
　 sstrPageVar = Value
End Property

Rem ## 是否刷新. 1 为刷新, 其他值则不刷新
Public Property Let intRefresh(Value)
　 sintRefresh = toNum(Value, 0)
End Property

Rem ## 获得当前页
Public Property Get intPageNow()
　 intPageNow = singPageNow
End Property

Rem ## 分页信息
Public Property Get strPageInfo()
　 strPageInfo = sstrPageInfo
End Property

Rem ## 取得记录集, 二维数组或字串, 在进行循环输出时必须用 IsArray() 判断
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 ## 初始化记录数
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 ## 初始化分页信息
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 = "首页上一页"
　 Else
　 sstrPageInfo = sstrPageInfo & " <a href=""" & surl & "1"">首页</a>"
　 sstrPageInfo = sstrPageInfo & " <a href=""" & surl & (sintPageNow - 1) & """>上一页</a>"
　 End If
　
　 If sintPageMax - sintPageNow < 1 then
　 sstrPageInfo = sstrPageInfo & " 下一页末页 "
　 Else
　 sstrPageInfo = sstrPageInfo & " <a href=""" & surl & (sintPageNow + 1) & """>下一页</a> "
　 sstrPageInfo = sstrPageInfo & " <a href=""" & surl & sintPageMax & """>末页</a> "
　 End If
　
　 sstrPageInfo = sstrPageInfo & " 页次：<strong><font color=""#990000"">" & sintPageNow & "</font> / " & sintPageMax & " </strong>"
　 sstrPageInfo = sstrPageInfo & " 共 <strong>" & sintRecordCount & "</strong> 条记录 <strong>" & sintPageSize & "</strong> 条/页 "
End Sub

Rem ## 长整数转换
Private function toNum(s, Default)
　 s = s & ""
　 If s <> "" And IsNumeric(s) Then
　 toNum = CLng(s)
　 Else
　 toNum = Default
　 End If
End function

Rem ## 类初始化
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>分页测试</title>
<style type="text/CSS">

</style>
<style type="text/css">

</style>
</head>
<body>
<table width="100%" border="0" cellspacing="0" cellpadding="4">
<tr>
<td> <%= 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> <%= arrRecordInfo(0, i)%></td>
　 <td> <%= arrRecordInfo(1, i)%></td>
　 <td> <%= arrRecordInfo(2, i)%></td>
</tr>
<%
　 Next
End If
%>
</table>
</div>
<table width="100%" border="0" cellspacing="0" cellpadding="4">
<tr>
<td> <%= strPageInfo%></td>
</tr>
</table>
<table width="100%" border="0" cellspacing="0" cellpadding="4">
<tr>
　 <td align="center"> <%= getTimeOver(1)%></td>
</tr>
</table>
</body>
</html>