asp翻页优化代码

asp翻页优化代码

<!---->

'//---- COCOON_自定义类_翻页优化代码 ----//'
Class cc_db_Pager

'//-------------------- 定义变量 --------------------//'
Private sTableName '//表名
Private sSqlString '//自定义Sql语句
Private aCondition() '//查询条件(数组)
Private sCondition '//查询条件(字符串)
Private iPage '//当前页码
Private iPageSize '//每页记录数
Private iPageCount '//总页数
Private iRecCount '//当前查询条件下的记录数
Private iTotalRecCount '//总记录数
Private sFields '//输出的字段名
Private sOrderBy '//排序字符串
Private sSql '//当前的查询语句
Private sPkey '//主键
Private oConn '//连接对象
Private iDefPageSize '//默认每页显示的记录数
Private sProjectName '/项目名
Private sVersion '/版本号
Private bShowError '//是否显示错误信息

'//-------------------- 事件、方法 --------------------//'
'//类初始化事件
Private Sub Class_Initialize()
ReDim aCondition(-1)
iPage = 1
iRecCount = Null
iTotalRecCount = Null
iPageCount = Null
bShowError = True
iPageSize = 10
sFields = "*"
sPkey = "ID"
sCondition = ""
sOrderBy = ""
sSqlString = ""
sProjectName = "COCOON 类系列 数据库翻页优化"
sVersion = "1.02"
End Sub

'//类结束事件
Private Sub Class_Terminate()
Set oConn = Nothing
End Sub

'//错误处理
Public Sub doError(s)
Dim sTmp
sTmp = CLng(Rnd() * 100)
Response.write( "

" )
Response.write( "" )
Response.write( "〖 CC_db_Pager 提示信息 〗
" )
Response.write( "

<nobr>" )
Response.write( "Description: " & s & "
" )
Response.write( "Provider: " & sProjectName )
Response.write( "  Version: " & sVersion & "
" )
Response.write( "</nobr>

" )
End Sub

'//产生分页的SQL语句
Public Function getSql()
Dim iStart, iEnd
Call makeCondition()
iStart = ( iPage - 1 ) * iPageSize
iEnd = iStart + iPageSize
getSql  = " SELECT DISTINCT " & sFields & " FROM ["&sTableName&"] " _
& " WHERE ["&sPKey&"] NOT IN ( " _
& "   SELECT TOP "&iStart&" ["&sPKey&"] FROM ["&sTableName&"] " & sCondition & " " & sOrderBy & " " _
& " )" _
& " AND ["&sPKey&"] IN ( " _
& "   SELECT TOP "&iEnd&" ["&sPKey&"] FROM ["&sTableName&"] " & sCondition & " " & sOrderBy & " " _
& " )" _
& " " & sOrderBy & " "
End Function

'//产生条件字符串
Private Sub makeCondition()
If UBound(aCondition)>=0 Then
sCondition = " WHERE " & Join(aCondition, " AND ")
End If
End Sub

'//计算总记录数（带条件）
Private Sub CaculateRecCount()
On Error Resume Next
Dim oRs
Call makeCondition()
Set oRs = oConn.Execute( "SELECT COUNT(["&sPKey&"]) FROM [" & sTableName & "]" & sCondition )
If Err Then
doError Err.Description
Response.End()
End If
iRecCount = oRs.Fields.Item(0).Value
Set oRs = Nothing
End Sub

'//计算总记录数（不带条件）
Private Sub CaculateTotalRecCount()
On Error Resume Next
Dim oRs
Set oRs = oConn.Execute( "SELECT COUNT(["&sPKey&"]) FROM [" & sTableName & "]" )
If Err Then
doError Err.Description
Response.End()
End If
iTotalRecCount = oRs.Fields.Item(0).Value
Set oRs = Nothing
End Sub

'//计算页数
Private Sub CaculatePageCount()
If isNull(iRecCount) Then CaculateRecCount()
If iRecCount = 0 Then iPageCount = 0 : Exit Sub
iPageCount = Abs( Int( 0 - (iRecCount / iPageSize) ) )
End Sub

'//增加条件
Public Sub AddCondition(s)
If Len(s)<0 Then Exit Sub
ReDim Preserve aCondition(UBound(aCondition)+1)
aCondition(UBound(aCondition)) = s
End Sub

'//版本信息
Public Function Information()
doError "Coding by Sunrise_Chen @ http://www.ccopus.com ."
End Function


'//-------------------- 输入属性 --------------------//'
'//定义连接对象
Public Property Set ActiveConnection(o)
Set oConn = o
End Property

'//定义查询表名
Public Property Let TableName(s)
sTableName = s
End Property

'//定义需要输出的字段名
Public Property Let Fields(s)
sFields = s
End Property

'//定义主键
Public Property Let Pkey(s)
sPkey = s
End Property

'//定义排序规则
Public Property Let OrderBy(s)
sOrderBy = " ORDER BY " & s & " "
End Property

'//定义每页的记录条数
Public Property Let PageSize(s)
iPageSize = s
If Not isNumeric(iPageSize) Then iPageSize = iDefaultPageSize
If CLng(iPageSize)<1 Then iPageSize = iDefaultPageSize
End Property

'//定义当前页码
Public Property Let Page(s)
iPage = s
If Not isNumeric(iPage) Then iPage = 1
If CLng(iPage)<1 Then iPage = 1
Call CaculatePageCount()
If CLng(iPage)>CLng(iPageCount) And iPageCount>0 Then iPage = iPageCount
End Property

'//自定义查询语句
Public Property Let Sql(s)
sSqlString = s
End Property

'//-------------------- 输出属性 --------------------//'
'//取得当前条件下的记录数
Public Property Get RecordCount
If isNull(iRecCount) Then CaculateRecCount()
RecordCount = iRecCount
End Property

'//取得当前页码
Public Property Get Page
Page = iPage
End Property

'//取得当前页码
Public Property Get AbsolutePage
AbsolutePage = iPage
End Property

'//取得当前查询的条件
Public Property Get Condition
If Len(sCondition)<1 Then makeCondition()
Condition = sCondition
End Property

'//取得总的记录数
Public Property Get TotalRecordCount
If isNull(iTotalRecCount) Then CaculateTotalRecCount()
TotalRecordCount = iTotalRecCount
End Property

'//取得总页数
Public Property Get PageCount
If isNull(iPageCount) Then CaculatePageCount()
PageCount = iPageCount
End Property

'//得到分页后的记录集
Public Property Get Recordset
On Error Resume Next
sSql = getSql()
Set Recordset = oConn.Execute( sSql )
If Err Then
If bShowError Then doError Err.Description
If Len(sSqlString)>0 Then
Set Recordset = oConn.Execute( sSqlString )
If Err Then
doError Err.Description
Response.End()
End If
Else
doError Err.Description
End If
End If
Err.Clear()
End Property

'//版本信息
Public Property Get Version
Version = sVersion
End Property

End Class