ASP unlimited stream paging code or instance

<%
'**【 Program Function]
'**
'** It performs paging operations on large databases, and the ideal number of operable data records is 2 million.
'** Or less (max level edition has no limit on the number of pages, regardless of the database size.
'** Unchanged). This is the paging program of the million level edition in the race Yang 1g, memory 512, Win2k ring.
'** Test data:
'**
'** Sqlserver 2 K + 0.1 million records + 20 records per page:
*** Average page turning speed: 45 Ms
'** Sqlserver 2 k + 1 million records + 20 records per page:
*** Average page turning speed: 350 ms
'**
'**
'** [Paging principle]
'**
'** This program no longer uses the Rs. pagesize Method for paging. the type of the cursor connecting to the database
'** Does not use Conn, 1, x, but Conn,. This should be the fastest cursor type.
'** Think this will complicate the program. On the contrary, the program is very simple. If you cannot understand it,
'** It should be my programming style that you are not used to, rather than complicated programs.
The center of the '** "infinite stream" page is that only the records to be displayed are read on each page.
'** The paging program prereads all the data, which is the biggest advantage of this program-less resources, the same
'** The processing speed has also been greatly improved, especially when the data volume is large, its speed advantage
'** The more obvious (1 million records are about ms ).
'** When the program is executed, use curcorbegin and curcorend to record the first entry
*** The id value of the record and the last record as the marker for the next page flip, and then use top XX to obtain
'** Displays the required data and records the id value.
'**
'** [Statement]
'**
'** This program is a shared version and is provided to programmers for research and use.
*** For modifying or other purposes, please respect the author's hard work and indicate the source.
'** If this program has defects such as errors and omissions or non-optimization, please go to the webdevelopment at http://www.csdn.net/
'** The ASP topic is discussed. Please do not stick to it for the sake of the development of the Chinese Software Industry :)
'**
'*************************************** *****************************

Option explicit
'Response. Flush
Dim begintime, endtime
Begintime = Timer
Dim Conn, sqlstr, RS, defrecordnum, cursorbegin, cursorend, curpagenum, hav
Defrecordnum = 20

'-------------- Get the relevant parameter ----------
If request ("cursorbegin") = "" Then cursorbegin = 0 else cursorbegin = request ("cursorbegin ")
If request ("cursorend") = "" Then cursorend = 0 else cursorend = request ("cursorend ")
If request ("curpagenum") <> "" then
Curpagenum = clng (Request ("curpagenum "))
If curpagenum <= 0 then curpagenum = 1
Else
Curpagenum = 1
End if
Hav = request ("hav ")
If hav = "" Then hav = "Next"
'---------------- End -----------------

'------------ function for displaying paging content --------
function turnpagefs (disprecordnum)
dim N
while not (RS. EOF) and n N = n + 1
response. write "" & _
"" & RS (0) & "" & _
"" & RS (1) & "" & _
"" & RS (2) & "" & _
"" & RS (3) & "" & _
"" & RS (4) & "" & _
"" & RS (5) & "" & _
""
if n = 1 then cursorbegin = RS (0)
if n = defrecordnum or Rs. EOF then cursorend = RS (0)
Rs. movenext
Wend
end function

'------------- Connect to the database -------------
Set conn = server. Createobject ("ADODB. Connection ")
'Sqlstr = "provider = Microsoft. Jet. oledb.4.0; Data Source =" & server. mappath ("mldata. mdb ")
Sqlstr = "driver = {sqlserver}; server = arbiter; uid = arbiter; Pwd = 123456; database = mldata"
Conn. Open sqlstr

'--------- Total number of records/total number of pages ---------
'-PS: Count (ID) is recommended. The ID is automatically numbered and indexed. Otherwise, the speed may be compromised.
'-PS: This is the most resource-consuming part of the program. If this program is canceled, the speed will be about 10 times faster.
Dim totalrecords, totalpages
Sqlstr = "select count (ID) as recordsum from ABC"
Set rs = conn. Execute (sqlstr, 0, 1)
Totalrecords = RS ("recordsum ")
Totalpages = ABS (INT (totalrecords/defrecordnum * (-1 )))
Rs. Close
Set rs = nothing

'-------- Select the corresponding SQL string according to hav -----
Select case (HAV)
Case "back"
Cursorend = cursorbegin
Sqlstr = "select top" & defrecordnum & "ID, title, filename, K, imgsize, nameson from ABC where ID <" & cursorbegin &_
"And ID in (select top" & defrecordnum & "id from ABC where ID <" & cursorbegin & "order by id desc) order by ID"
Case "Next"
Sqlstr = "select top" & defrecordnum & "ID, title, filename, K, imgsize, nameson from ABC where ID>" & cursorend &_
"Order by ID"
End select
Set rs = conn. Execute (sqlstr, 0, 1)
%>
<HTML>
<Head>
<Title> "infinite stream" Paging program Author: arbiter </title>
<Meta http-equiv = "Content-Type" content = "text/html; charset = gb2312">
<Style type = "text/CSS"> TD, BR, Div, P, body {font-size: 12px} </style>
</Head>
<Body bgcolor = "# ffffff" leftmargin = "0" topmargin = "0">
<Table width = "100%" border = "0" cellspacing = "0" cellpadding = "3" bgcolor = "# e2f5fe">
<Tr align = "center">
<TD colspan = "2"> <% response. Write curpagenum & "/" & totalpages & "Total number of page records:" & totalrecords %> </TD>
<TD> <a href = "mllist. asp"> homepage </a> <a href = javascript: turnpage ('back');> previous page </a>
<A href = javascript: turnpage ('Next');> next page </a> </TD>
</Tr>
</Table>
<Table width = "100%" border = "1" cellspacing = "0" cellpadding = "3" bgcolor = "# cccccc">
<Tr>
<TD> id </TD>
<TD> title </TD>
<TD> filename </TD>
<TD> size </TD>
<TD> size </TD>
<TD> Category </TD>
</Tr>
<%
Turnpagefs (defrecordnum)
Rs. Close
Set rs = nothing
Conn. Close
Set conn = nothing
%>
</Table>
<Table width = "100%" border = "0" cellspacing = "0" cellpadding = "3" bgcolor = "# e2f5fe">
<Tr align = "center">
<TD colspan = "2"> <% response. Write curpagenum & "/" & totalpages & "Total number of page records:" & totalrecords %> </TD>
<TD> <a href = "mllist. asp"> homepage </a> <a href = javascript: turnpage ('back');> previous page </a>
<A href = javascript: turnpage ('Next');> next page </a> </TD>
</Tr>
</Table>
<%
Endtime = Timer
Response. Write "<br> program execution time:" & (endtime-begintime) * 1000 & "millisecond"
Response. write "the id value (cursorbegin) of the first record =" & cursorbegin &""
Response. write "the id value (cursorend) of the last record =" & cursorend & "<br>"
%>
<Script language = "JavaScript">
Function turnpage (func ){
VaR curpagenum = <% = curpagenum %>; // obtain the current page number
VaR cursorbegin = <% = cursorbegin %>; // obtain the id value of the first displayed record
VaR cursorend = <% = cursorend %>; // obtain the ID of the last displayed record
VaR totalpages = <% = totalpages %>; // retrieves the total number of pages

var backurl = 'mllist. asp? Curpagenum = '+ (CurPageNum-1) +' & cursorbegin = '+ cursorbegin +' & cursorend = '+ cursorend +' & hav = back';
var nexturl = 'mllist. asp? Curpagenum = '+ (curpagenum + 1) +' & cursorbegin = '+ cursorbegin +' & cursorend = '+ cursorend +' & hav = next ';
If (curpagenum <= 1 & func = 'back') {
location. href = '#';
}else if (curpagenum >=totalpages & func = 'Next') {
location. href = '#';
}else if (func = 'back') {
location. href = backurl;
}else if (func = 'Next') {
location. href = nexturl;
}< BR >}< br>


references: http://hi.baidu.com/happyredtea/blog/item/82dc965868d2c680800a18a9.html