Help on Updated data info ????

[Guest]

Dear all,

I ma building an ASP.NET 1.1 application which collects data from an SQL
server database. My customer use an internet browser to read particular
information from SQL server.

A remote system is periodically updating tables. Is there a way to informeds
my user with a message that table has been updated and refresh of the page si
needed for last data if desired ???

 

[Jesús López]

A web server that uses the traditional http request - response pattern has
no way to notify the web browser about something. However the web browser
can periodically poll the server asking for changes. I suggest you to use an
Ajax approach to implement the polling technique. The web browser can call
out-of-band a web service on your web application. This web service would
inform whether changes have happened or not. There are are lot of Ajax
libraries out there, but many people are using Ajax.net:

http://ajax.schwarz-interactive.de/csharpsample/default.aspx

Microsoft is developping an Ajax library code-named Atlas, but it is for
ASP.NET 2.0 and you may not use at this moment in a production environment.

If the remote system is under your control, you may want to modify it in a
way that the remote system informs the web application about changes.

If the remote system is not under your control you may want to create
triggers on the database that inform the web application about changes. If
you are using SQL Server 2005 you can writte CLR triggers. If you are using
SQL Server 2000 you can use sp_OA?? stored procedures to create and use
"msxml2.XMLHTTP" objects to inform the web application about changes.
Another aternative is that you web application polls SQL Server looking for
changes.

Regards from Madrid (Spain)

Jesús López
VB MVP