asked on

VBScript Pagination - ASP

Hello,

I'm building a site in ASP VBScript. Historically I have used the ASP Recordset to query a database, however I'm growing more aware that whilst my repeat region may only show 10 records, the recordset grabs all the data,... and that this impacts on resource use.

Therefore I've started to query the database though Stored Procedures like so -

CREATE PROCEDURE [dbo].[returnresults](
@offset int,
@pagecount int)
AS
BEGIN
      SET NOCOUNT ON;
      IF @offset is null set @offset = 1
      SET @pagecount = @offset + 19
      BEGIN
      -- THE ROW_NUMBER CAN BE USED IN COMMON TABEL EXPRESSION
            ;WITH JBCTE
            AS(
            SELECT 
                  ID,         
                  Row1,         
                  Row2         
                  ROW_NUMBER() OVER (ORDER BY [ID] desc) AS RowNum  
            FROM       dbo.datatable
            )
            SELECT	ID,         
					Row1,         
					Row2         
            FROM	JBCTE 
            WHERE   RowNum between @offset and @pagecount
            ORDER BY ID DESC
      END
END
GO

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as it will only return the number of results that I want to show on each page.

I've also taken to running a separate SP in order to return the count of all results -

CREATE PROCEDURE [dbo].[returnresultsCount]
AS
BEGIN
      SET NOCOUNT ON;
      BEGIN
      -- THE ROW_NUMBER CAN BE USED IN COMMON TABEL EXPRESSION

            SELECT 
                  COUNT(ID) Results         
            FROM       dbo.datatable
      END
END
GO

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Now historically, I would use a dreamweaver extension (I know...) to write the code to produce the pagination navigation at the bottom of the page, the code for this reads like -----

<%
'  *** Recordset Stats, Move To Record, and Go To Record: declare stats variables

Dim results_total
Dim results_first
Dim results_last

' set the record count
results_total = results.RecordCount

' set the number of rows displayed on this page
If (results_numRows < 0) Then
  results_numRows = results_total
Elseif (results_numRows = 0) Then
  results_numRows = 1
End If

' set the first and last displayed record
results_first = 1
results_last  = results_first + results_numRows - 1

' if we have the correct record count, check the other stats
If (results_total <> -1) Then
  If (results_first > results_total) Then
    results_first = results_total
  End If
  If (results_last > results_total) Then
    results_last = results_total
  End If
  If (results_numRows > results_total) Then
    results_numRows = results_total
  End If
End If
%>
<%
' *** Recordset Stats: if we don't know the record count, manually count them

If (results_total = -1) Then

  ' count the total records by iterating through the recordset
  results_total=0
  While (Not results.EOF)
    results_total = results_total + 1
    results.MoveNext
  Wend

  ' reset the cursor to the beginning
  If (results.CursorType > 0) Then
    results.MoveFirst
  Else
    results.Requery
  End If

  ' set the number of rows displayed on this page
  If (results_numRows < 0 Or results_numRows > results_total) Then
    results_numRows = results_total
  End If

  ' set the first and last displayed record
  results_first = 1
  results_last = results_first + results_numRows - 1
  
  If (results_first > results_total) Then
    results_first = results_total
  End If
  If (results_last > results_total) Then
    results_last = results_total
  End If

End If
%>
<%
Dim MM_paramName 
%>
<%
' *** Move To Record and Go To Record: declare variables

Dim MM_rs
Dim MM_rsCount
Dim MM_size
Dim MM_uniqueCol
Dim MM_offset
Dim MM_atTotal
Dim MM_paramIsDefined

Dim MM_param
Dim MM_index

Set MM_rs    = results
MM_rsCount   = results_total
MM_size      = results_numRows
MM_uniqueCol = ""
MM_paramName = ""
MM_offset = 0
MM_atTotal = false
MM_paramIsDefined = false
If (MM_paramName <> "") Then
  MM_paramIsDefined = (Request.QueryString(MM_paramName) <> "")
End If
%>
<%
' *** Move To Record: handle 'index' or 'offset' parameter

if (Not MM_paramIsDefined And MM_rsCount <> 0) then

  ' use index parameter if defined, otherwise use offset parameter
  MM_param = Request.QueryString("index")
  If (MM_param = "") Then
    MM_param = Request.QueryString("offset")
  End If
  If (MM_param <> "") Then
    MM_offset = Int(MM_param)
  End If

  ' if we have a record count, check if we are past the end of the recordset
  If (MM_rsCount <> -1) Then
    If (MM_offset >= MM_rsCount Or MM_offset = -1) Then  ' past end or move last
      If ((MM_rsCount Mod MM_size) > 0) Then         ' last page not a full repeat region
        MM_offset = MM_rsCount - (MM_rsCount Mod MM_size)
      Else
        MM_offset = MM_rsCount - MM_size
      End If
    End If
  End If

  ' move the cursor to the selected record
  MM_index = 0
  While ((Not MM_rs.EOF) And (MM_index < MM_offset Or MM_offset = -1))
    MM_rs.MoveNext
    MM_index = MM_index + 1
  Wend
  If (MM_rs.EOF) Then 
    MM_offset = MM_index  ' set MM_offset to the last possible record
  End If

End If
%>
<%
' *** Move To Record: if we dont know the record count, check the display range

If (MM_rsCount = -1) Then

  ' walk to the end of the display range for this page
  MM_index = MM_offset
  While (Not MM_rs.EOF And (MM_size < 0 Or MM_index < MM_offset + MM_size))
    MM_rs.MoveNext
    MM_index = MM_index + 1
  Wend

  ' if we walked off the end of the recordset, set MM_rsCount and MM_size
  If (MM_rs.EOF) Then
    MM_rsCount = MM_index
    If (MM_size < 0 Or MM_size > MM_rsCount) Then
      MM_size = MM_rsCount
    End If
  End If

  ' if we walked off the end, set the offset based on page size
  If (MM_rs.EOF And Not MM_paramIsDefined) Then
    If (MM_offset > MM_rsCount - MM_size Or MM_offset = -1) Then
      If ((MM_rsCount Mod MM_size) > 0) Then
        MM_offset = MM_rsCount - (MM_rsCount Mod MM_size)
      Else
        MM_offset = MM_rsCount - MM_size
      End If
    End If
  End If

  ' reset the cursor to the beginning
  If (MM_rs.CursorType > 0) Then
    MM_rs.MoveFirst
  Else
    MM_rs.Requery
  End If

  ' move the cursor to the selected record
  MM_index = 0
  While (Not MM_rs.EOF And MM_index < MM_offset)
    MM_rs.MoveNext
    MM_index = MM_index + 1
  Wend
End If
%>
<%
' *** Move To Record: update recordset stats

' set the first and last displayed record
results_first = MM_offset + 1
results_last  = MM_offset + MM_size

If (MM_rsCount <> -1) Then
  If (results_first > MM_rsCount) Then
    results_first = MM_rsCount
  End If
  If (results_last > MM_rsCount) Then
    results_last = MM_rsCount
  End If
End If

' set the boolean used by hide region to check if we are on the last record
MM_atTotal = (MM_rsCount <> -1 And MM_offset + MM_size >= MM_rsCount)
%>
<%
' *** Go To Record and Move To Record: create strings for maintaining URL and Form parameters

Dim MM_keepNone
Dim MM_keepURL
Dim MM_keepForm
Dim MM_keepBoth

Dim MM_removeList
Dim MM_item
Dim MM_nextItem

' create the list of parameters which should not be maintained
MM_removeList = "&index="
If (MM_paramName <> "") Then
  MM_removeList = MM_removeList & "&" & MM_paramName & "="
End If

MM_keepURL=""
MM_keepForm=""
MM_keepBoth=""
MM_keepNone=""

' add the URL parameters to the MM_keepURL string
For Each MM_item In Request.QueryString
  MM_nextItem = "&" & MM_item & "="
  If (InStr(1,MM_removeList,MM_nextItem,1) = 0) Then
    MM_keepURL = MM_keepURL & MM_nextItem & Server.URLencode(Request.QueryString(MM_item))
  End If
Next

' add the Form variables to the MM_keepForm string
For Each MM_item In Request.Form
  MM_nextItem = "&" & MM_item & "="
  If (InStr(1,MM_removeList,MM_nextItem,1) = 0) Then
    MM_keepForm = MM_keepForm & MM_nextItem & Server.URLencode(Request.Form(MM_item))
  End If
Next

' create the Form + URL string and remove the intial '&' from each of the strings
MM_keepBoth = MM_keepURL & MM_keepForm
If (MM_keepBoth <> "") Then 
  MM_keepBoth = Right(MM_keepBoth, Len(MM_keepBoth) - 1)
End If
If (MM_keepURL <> "")  Then
  MM_keepURL  = Right(MM_keepURL, Len(MM_keepURL) - 1)
End If
If (MM_keepForm <> "") Then
  MM_keepForm = Right(MM_keepForm, Len(MM_keepForm) - 1)
End If

' a utility function used for adding additional parameters to these strings
Function MM_joinChar(firstItem)
  If (firstItem <> "") Then
    MM_joinChar = "&"
  Else
    MM_joinChar = ""
  End If
End Function
%>
<%
' *** Move To Record: set the strings for the first, last, next, and previous links

Dim MM_keepMove
Dim MM_moveParam
Dim MM_moveFirst
Dim MM_moveLast
Dim MM_moveNext
Dim MM_movePrev

Dim MM_urlStr
Dim MM_paramList
Dim MM_paramIndex
Dim MM_nextParam

MM_keepMove = MM_keepBoth
MM_moveParam = "index"

' if the page has a repeated region, remove 'offset' from the maintained parameters
If (MM_size > 1) Then
  MM_moveParam = "offset"
  If (MM_keepMove <> "") Then
    MM_paramList = Split(MM_keepMove, "&")
    MM_keepMove = ""
    For MM_paramIndex = 0 To UBound(MM_paramList)
      MM_nextParam = Left(MM_paramList(MM_paramIndex), InStr(MM_paramList(MM_paramIndex),"=") - 1)
      If (StrComp(MM_nextParam,MM_moveParam,1) <> 0) Then
        MM_keepMove = MM_keepMove & "&" & MM_paramList(MM_paramIndex)
      End If
    Next
    If (MM_keepMove <> "") Then
      MM_keepMove = Right(MM_keepMove, Len(MM_keepMove) - 1)
    End If
  End If
End If

' set the strings for the move to links
If (MM_keepMove <> "") Then 
  MM_keepMove = Server.HTMLEncode(MM_keepMove) & "&"
End If

MM_urlStr = Request.ServerVariables("URL") & "?" & MM_keepMove & MM_moveParam & "="

MM_moveFirst = MM_urlStr & "0"
MM_moveLast  = MM_urlStr & "-1"
MM_moveNext  = MM_urlStr & CStr(MM_offset + MM_size)
If (MM_offset - MM_size < 0) Then
  MM_movePrev = MM_urlStr & "0"
Else
  MM_movePrev = MM_urlStr & CStr(MM_offset - MM_size)
End If
%>

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Server Side - where results is the recordset

and client side -

<%
TFM_MiddlePages = 6
TFM_delimiter = " "
TFM_startLink = MM_offset + 1 - MM_size * (int(TFM_middlePages/2))
If MM_offset > 0 Then TFM_LimitPageEndCount = int(TFM_startLink/MM_size)
If TFM_startLink < 1 Then 
	TFM_startLink = 1
	TFM_LimitPageEndCount = 0
End If
TFM_endLink = MM_size * TFM_MiddlePages + TFM_startLink - 1
If TFM_endLink > results_total Then TFM_endLink = results_total 
For i = TFM_startLink to TFM_endLink Step MM_size
  TFM_LimitPageEndCount = TFM_LimitPageEndCount + 1
  if i <> MM_offset + 1 Then
    Response.Write("<a href=""" & Request.ServerVariables("URL") & "?" & MM_keepMove & "offset=" & i-1 & """>")
    Response.Write(TFM_LimitPageEndCount & "</a>")
  else
    Response.Write("<strong>")
    Response.Write(TFM_LimitPageEndCount & "</strong>")
  End if
  if(i <= TFM_endLink - MM_size) then Response.Write(TFM_delimiter)
Next
%>

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This won't work with the way I am now querying the database, I am returning rowcount and total records between my two SPs.

I'm really keen to find a way to bespoke this code so that it works with my stored procedures....

I'm assuming that my stored procedures provide all the elements needed..

Any suggestions?

Thank you

Scott Fell

First when I use stored procedures, I just create an include file that is nothing more then a function that accesses the stored procedure. If you are doing this for just for navigation, it is easier to just run your query on your page as you normally do, but use getRows() instead of the repeat region. Very fast and efficient. And you can re use the for next in your footer without having to access the db again because it is in an array.

<%@LANGUAGE="VBSCRIPT" CODEPAGE="65001"%>
<%
Dim rsNav
Dim rsNav_cmd
Dim rsNav_numRows

Set rsNav_cmd = Server.CreateObject ("ADODB.Command")
rsNav_cmd.ActiveConnection = MyConnectionString
rsNav_cmd.CommandText = "SELECT  Text, Link FROM dbo.tNavl ORDER BY Sort" 
rsNav_cmd.Prepared = true

Set rsNav = rsNav_cmd.Execute
rsNav_numRows = 0
%>
<%
if not rsNav.bof or nor rsNav.eof then
	arrNav=rsNav.getrows()
end if
%>
<%
rsNav.Close()
Set rsNav = Nothing
%>

<style>
ul#nav ul{ /* style for nav */}
ul#nav li{/* style for nav */}

</style>
<ul id="nav">
<%
 For r = LBound(arrNav, 2) To UBound(arrNav, 2)
    		navText 		=arrIssues(0, r)
			navLink		=arrIssues(1, r)
			
			response.write "<li><a href="""&navLink&""">"&navText&"</a></li>"
next
%>
</ul>

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garethtnash

ASKER

Thanks Padas,

couple of things, i only want to display x links along the bottom, like Google, would this work?

How does the recordset work with the SP, I'm a little confused?

Thank you

ASKER CERTIFIED SOLUTION

Scott Fell

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garethtnash

ASKER

Hi Padas,

Thanks.

Sorry I probably should have explained better, the view I'm querying contains 25,000 records, and 1 of the columns returned is an nvarchar(max) column, albeit we only return the first 420 characters.

What I'm trying to avoid is the worst case scenario whereby all 25,000 are returned by the query, only to have the page only write 10 or 20 of these, as this would use a mass of resources and take forever to load, which is why I'm using a CTE, to only write x records at a time.

Which leaves me with the paging navigation..

I think editing this somehow will work --

<%
TFM_MiddlePages = 6
TFM_delimiter = " "
TFM_startLink = MM_offset + 1 - MM_size * (int(TFM_middlePages/2)) 'URL Offset +1 - number of records on page * (middlepages/2)
If MM_offset > 0 Then TFM_LimitPageEndCount = int(TFM_startLink/MM_size)
If TFM_startLink < 1 Then 
	TFM_startLink = 1
	TFM_LimitPageEndCount = 0
End If
TFM_endLink = MM_size * TFM_MiddlePages + TFM_startLink - 1
If TFM_endLink > results_total Then TFM_endLink = results_total 
For i = TFM_startLink to TFM_endLink Step MM_size
  TFM_LimitPageEndCount = TFM_LimitPageEndCount + 1
  if i <> MM_offset + 1 Then
    Response.Write("<a href=""" & Request.ServerVariables("URL") & "?" & MM_keepMove & "offset=" & i-1 & """>")
    Response.Write(TFM_LimitPageEndCount & "</a>")
  else
    Response.Write("<strong>")
    Response.Write(TFM_LimitPageEndCount & "</strong>")
  End if
  if(i <= TFM_endLink - MM_size) then Response.Write(TFM_delimiter)
Next
%>

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providing that I am able to get values for -

MM_offset
MM_size
results_total

Hope that makes better sense?

Thanks for your help so far.

G