On any change or update

I am wiriting a C# application that stores availabilty information in a tabl
e
ie UserName, UserAvailable (just to keep it simple)
I am looking for a recommendation for the best way to have the SQL database
notify my c# client that any data in this table has been changed.
In my old non .net application I used a client/server model where the
server watched for changes and sent messages to each registered client but n
o
data was ever saved. Two of my goals with the new application are eliminatin
g
the server application and saving the data to a SQL db.
Currently I have my application re-examine the table every n-seconds but
this is far from optimal. Any suggestions would be highly appreciated.
Regards,
SeanHi
What is your SQL Server vesion?
If it is SQL Server 2000 , I think you may want to consider using triggers
to examine "deleted" and "inserted" virtual tables
Does your App make changes too?
"Codesmith" <Codesmith@.discussions.microsoft.com> wrote in message
news:8F93298C-EBD9-4CE4-A7C9-8DA9E9731908@.microsoft.com...
>I am wiriting a C# application that stores availabilty information in a
>table
> ie UserName, UserAvailable (just to keep it simple)
> I am looking for a recommendation for the best way to have the SQL
> database
> notify my c# client that any data in this table has been changed.
> In my old non .net application I used a client/server model where the
> server watched for changes and sent messages to each registered client but
> no
> data was ever saved. Two of my goals with the new application are
> eliminating
> the server application and saving the data to a SQL db.
> Currently I have my application re-examine the table every n-seconds but
> this is far from optimal. Any suggestions would be highly appreciated.
> Regards,
> Sean|||If you are on, or can upgrade to, SQL Serer 2005, read up on Query Notificat
ions.
Tibor Karaszi, SQL Server MVP
http://www.karaszi.com/sqlserver/default.asp
http://www.solidqualitylearning.com/
Blog: http://solidqualitylearning.com/blogs/tibor/
"Codesmith" <Codesmith@.discussions.microsoft.com> wrote in message
news:8F93298C-EBD9-4CE4-A7C9-8DA9E9731908@.microsoft.com...
>I am wiriting a C# application that stores availabilty information in a tab
le
> ie UserName, UserAvailable (just to keep it simple)
> I am looking for a recommendation for the best way to have the SQL databas
e
> notify my c# client that any data in this table has been changed.
> In my old non .net application I used a client/server model where the
> server watched for changes and sent messages to each registered client but
no
> data was ever saved. Two of my goals with the new application are eliminat
ing
> the server application and saving the data to a SQL db.
> Currently I have my application re-examine the table every n-seconds but
> this is far from optimal. Any suggestions would be highly appreciated.
> Regards,
> Sean|||There are many approaches for implementing that, the best and sexiest
solution is to use Query Notification as Tibor said. There are other
mechanisms for doing this (including calling Message Queues...), but
not as easy to use as QN :-)
HTH, jens Suessmeyer.|||Tibor,
Thanks for your responce. After reviewing the documentaion on the MSDN web
page this sounds like just what I had in mind.
Do you know if the service broker feature is available in the 2005 Express
edition of SQL?
"Tibor Karaszi" wrote:

> If you are on, or can upgrade to, SQL Serer 2005, read up on Query Notific
ations.
>|||Hi,
http://www.microsoft.com/sql/prodin...e-features.mspx
Service Broker (Subscriber only) --means yes, you can.
HTH, Jens Suessmeyer.|||Hi Jens!
the way I read the part "subscriber only" is that you cannot insert into a q
ueue on Express. To me,
this sounds like Express does not support query notifications. But I happily
admit that I'm only
guessing here. ;-)
Tibor Karaszi, SQL Server MVP
http://www.karaszi.com/sqlserver/default.asp
http://www.solidqualitylearning.com/
Blog: http://solidqualitylearning.com/blogs/tibor/
"Jens" <Jens@.sqlserver2005.de> wrote in message
news:1136912680.595505.22710@.g43g2000cwa.googlegroups.com...
> Hi,
> http://www.microsoft.com/sql/prodin...e-features.mspx
> Service Broker (Subscriber only) --means yes, you can.
>
> HTH, Jens Suessmeyer.
>|||You are right I just read down the white paper, you can subscribe
within broker queues outside the SQL Server Express Editions, so you
just can be notified. So even default queues are not creaetable. Sorry
for the wrong information to the original poster, thanks to Tibor.
-Jens.|||Service Broker is available in SQL Express 2005.
The only restriction is that when exchanging messages between separate SQL
instances, the message has to pass trough a higher version. That is, you
cannot send a message from a SQL Express to another SQL Express directly.
Since you're interested in Query Notifications, you will probably keep the
messages local within the SQL Express instance, so this limitation won't
affect you whatsoever.
This posting is provided "AS IS" with no warranties, and confers no rights.
HTH,
~ Remus Rusanu
SQL Service Broker
http://msdn2.microsoft.com/en-us/library/ms166043(en-US,SQL.90).aspx
"Codesmith" <Codesmith@.discussions.microsoft.com> wrote in message
news:7DF1F9B5-19F0-4E41-AA75-D2B19DA5EE7B@.microsoft.com...
> Tibor,
> Thanks for your responce. After reviewing the documentaion on the MSDN web
> page this sounds like just what I had in mind.
> Do you know if the service broker feature is available in the 2005 Express
> edition of SQL?
>
> "Tibor Karaszi" wrote:
>|||Sorry, not true Tibor. The short story is that as long as you are working
within the same instance (which is the only way query notifications work
with the default listener) SQL Express Service Broker is 100% equivalent to
all the other SKU's. If you are talking between sku's, there is a small
restriction as Remus pointed out.
This posting is provided "AS IS" with no warranties, and confers no rights.
Use of included script samples are subject to the terms specified at
http://www.microsoft.com/info/cpyright.htm
"Tibor Karaszi" <tibor_please.no.email_karaszi@.hotmail.nomail.com> wrote in
message news:uiQOc2gFGHA.3280@.TK2MSFTNGP10.phx.gbl...
> Hi Jens!
> the way I read the part "subscriber only" is that you cannot insert into a
> queue on Express. To me, this sounds like Express does not support query
> notifications. But I happily admit that I'm only guessing here. ;-)
> --
> Tibor Karaszi, SQL Server MVP
> http://www.karaszi.com/sqlserver/default.asp
> http://www.solidqualitylearning.com/
> Blog: http://solidqualitylearning.com/blogs/tibor/
>
> "Jens" <Jens@.sqlserver2005.de> wrote in message
> news:1136912680.595505.22710@.g43g2000cwa.googlegroups.com...
>