Draft for Information Only

Content


        Request Object
 Request.QueryString Collection
  
        Syntax:
  
        Parameters:
  
        Remarks:
  
        Examples:

Request Object

The main function of Request object is the retrieving of HTTP request variables from the client.

Request.QueryString Collection

Request.QueryString Collection retrieves the variable values of query string which is sent in the HTTP request.

Syntax:

Request.QueryString(variable)[(index)|.Count]

Or in an ASP file. Imply

<% Request.QueryString(variable)[(index)|.Count] %>

Parameters:

variable

The parameter "variable" is the name of the variable in the HTTP query string to be retrieved. The data type of "variable" is string and is enclosed by quotation marks (" ").

index

The optional parameter "index" is the number of the index of a variable with multiple values in the HTTP query string to be retrieved. The data type of "index" is an integer and the range is from 1 to Request.QueryString(variable).Count

.Count

The parameter "Count" is the optional information of the parameter "variable" with delimeter ".". The parameter "Count" is a read-only attribute to return the total number of the available values of the parameter " variable".

Remarks:

The HTTP query string is the string following the question mark (?) in an HTTP request. For example:

http://127.0.0.1/default.asp?qrystring=qrystringtvalue

Although query string are usually generated by a response page output, query string are only strings contained in an request headers. The values of query strings can also be generated by any user. Therefore header data or user input should be encoded or be validated before using.

The QueryString Collection is the detailed version of the Query_String variable of the ServerVariables Collection. With the Request.QueryString Collection, the value of query string can be retrieved by name.

For variable with multiple values, the value of Request.QueryString(variable) will be in form of an array of all values of the variable in the Query_String. And the number of multiple values of the variable can be obtained by Request.QueryString(variable).Count. For single value varible, Request.QueryString(variable).Count equal to 1. If the variable does not exist, Request.QueryString(variable).Count equal to 0.

And therefore the multiple values of a variable can be referenced by the parameter "index", Request.QueryString(variable)(index). and the range of the index is from 1 to Request.QueryString(variable).Count.

However, if the index is not specified for a multiple values variable, the Request.QueryString(variable) will return all values in the form of comma-delimited string.

Besides, if there is no specified variable for the Request.QueryString(), the Request.QueryString() will return the unparsed QueryString data.

Since the multiple values of a variable is in the form of an array, the values of the variable can be retrieved using a for index loop or a for each element loop.

Examples:

HTTP Request

HTTP Request:

http://127.0.0.1/default.asp?A=9&B=1&B=2
With no variable specified in Request.QueryString

ASP script command:

<%= Request.QueryString %>

HTTP response output (Buffered):
A=9&B=1&B=2

HTML web page ouput:

A=9&B=1&B=2
With variable A specified in Request.QueryString

ASP script command:

<%= Request.QueryString("A") %>

HTTP response output (Buffered):
9

HTML web page ouput:

9
With variable B specified in Request.QueryString

ASP script command:

<%= Request.QueryString("B") %>

HTTP response output (Buffered):
1, 2

HTML web page ouput:

1, 2
With variable B specified in Request.QueryString().Count

ASP script command:

<%= Request.QueryString("B").Count %>

HTTP response output (Buffered):
2

HTML web page ouput:

2
Loop for all values in variable B specified in Request.QueryString() by count

ASP script command:

<%
For i=1 to Request.QueryString("B").count
Response.Write Request.QueryString("B")(i) & " "
Next
%>

HTTP response output (Buffered):
1 
2 

HTML web page ouput:

1
2
Loop for all values in variable B specified in Request.QueryString() by item

ASP script command:

<%
For Each item in Request.QueryString("B")
Response.Write item & " "
Next
%>

HTTP response output (Buffered):
1 
2 

HTML web page ouput:

1
2

©sideway

ID: 120200017 Last Updated: 2/7/2012 Revision: 0 Ref:

References

Active Server Pages, , http://msdn.microsoft.com/en-us/library/aa286483.aspx
ASP Overview, , http://msdn.microsoft.com/en-us/library/ms524929%28v=vs.90%29.aspx
ASP Best Practices, , http://technet.microsoft.com/en-us/library/cc939157.aspx
ASP Built-in Objects, , http://msdn.microsoft.com/en-us/library/ie/ms524716(v=vs.90).aspx
Response Object, , http://msdn.microsoft.com/en-us/library/ms525405(v=vs.90).aspx
Request Object, , http://msdn.microsoft.com/en-us/library/ms524948(v=vs.90).aspx
Server Object (IIS), , http://msdn.microsoft.com/en-us/library/ms525541(v=vs.90).aspx
Application Object (IIS), , http://msdn.microsoft.com/en-us/library/ms525360(v=vs.90).aspx
Session Object (IIS), , http://msdn.microsoft.com/en-us/library/ms524319(8v=vs.90).aspx
ASPError Object, , http://msdn.microsoft.com/en-us/library/ms524942(v=vs.90).aspx
ObjectContext Object (IIS), , http://msdn.microsoft.com/en-us/library/ms525667(v=vs.90).aspx
Debugging Global.asa Files, , http://msdn.microsoft.com/en-us/library/aa291249(v=vs.71).aspx
How to: Debug Global.asa files, , http://msdn.microsoft.com/en-us/library/ms241868(v=vs.80).aspx
Calling COM Components from ASP Pages, , http://msdn.microsoft.com/en-us/library/ms524620(v=VS.90).aspx
IIS ASP Scripting Reference, , http://msdn.microsoft.com/en-us/library/ms524664(v=vs.90).aspx
ASP Keywords, , http://msdn.microsoft.com/en-us/library/ms524672(v=vs.90).aspx
Creating Simple ASP Pages, , http://msdn.microsoft.com/en-us/library/ms524741(v=vs.90).aspx
Including Files in ASP Applications, , http://msdn.microsoft.com/en-us/library/ms524876(v=vs.90).aspx
ASP Overview, , http://msdn.microsoft.com/en-us/library/ms524929(v=vs.90).aspx
FileSystemObject Object, , http://msdn.microsoft.com/en-us/library/z9ty6h50(v=vs.84).aspx
http://msdn.microsoft.com/en-us/library/windows/desktop/ms675944(v=vs.85).aspx, , ADO Object Model
ADO Fundamentals, , http://msdn.microsoft.com/en-us/library/windows/desktop/ms680928(v=vs.85).aspx