Hi

I'm not sure whether I've given this post the correct title, but I'm a
bit unsure of where to put it.

I have a database that holds information about several of our users.
This database is stored on a central server, with an application that
periodically performs some processing, which may or may not update the
database. It is possible that some times this data will update several
times a minute.

Here's my problem - I would like to create an application, in a remote
location to the main database server that displays the database
contents. This applications would need to update its view of the
database as soon as the database changes in order to ensure that only
the most up to date information is being displayed.

I've previously done this by periodically re-reading the database and
updating the fields that have changed on screen, however as I add more
terminals, this may cause a problem. So ideally I would like a
callback or trigger to be called when the database updates that
informs the correct client, so that it can update it's screen
accordingly.

Is this possible, or am I barking up the wrong tree? Is there a better
way of doing it? I'd be very grateful if you could give me your
thoughts.

I am developing the main client application in C#, and the database is
currently MySQL. It would be possible to change the database if this
made things easier, however it would have to be a free alternative!

Many thanks

Steve

Can you just pull the contents of the database at regular intervals? How
current does the remote application's view need to be? And how much data are
we talking about? 100s of rows, 1000s?


<(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Hi
>
> I'm not sure whether I've given this post the correct title, but I'm a
> bit unsure of where to put it.
>
> I have a database that holds information about several of our users.
> This database is stored on a central server, with an application that
> periodically performs some processing, which may or may not update the
> database. It is possible that some times this data will update several
> times a minute.
>
> Here's my problem - I would like to create an application, in a remote
> location to the main database server that displays the database
> contents. This applications would need to update its view of the
> database as soon as the database changes in order to ensure that only
> the most up to date information is being displayed.
>
> I've previously done this by periodically re-reading the database and
> updating the fields that have changed on screen, however as I add more
> terminals, this may cause a problem. So ideally I would like a
> callback or trigger to be called when the database updates that
> informs the correct client, so that it can update it's screen
> accordingly.
>
> Is this possible, or am I barking up the wrong tree? Is there a better
> way of doing it? I'd be very grateful if you could give me your
> thoughts.
>
> I am developing the main client application in C#, and the database is
> currently MySQL. It would be possible to change the database if this
> made things easier, however it would have to be a free alternative!
>
> Many thanks
>
> Steve
>

Check out Notification Services. It can do what you want. There are a number
of issues involved here including adverse performance, but it can notify you
if specific tables or their contents are changed.

--
____________________________________
William (Bill) Vaughn
Author, Mentor, Consultant, Dad, Grandpa
Microsoft MVP
INETA Speaker
www.betav.com
www.betav.com/blog/billva
Please reply only to the newsgroup so that others can benefit.
This posting is provided "AS IS" with no warranties, and confers no rights.
__________________________________
Visit www.hitchhikerguides.net to get more information on my latest book:
Hitchhiker's Guide to Visual Studio and SQL Server (7th Edition)
and Hitchhiker's Guide to SQL Server 2005 Compact Edition (EBook)
-----------------------------------------------------------------------------------------------------------------------

<(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Hi
>
> I'm not sure whether I've given this post the correct title, but I'm a
> bit unsure of where to put it.
>
> I have a database that holds information about several of our users.
> This database is stored on a central server, with an application that
> periodically performs some processing, which may or may not update the
> database. It is possible that some times this data will update several
> times a minute.
>
> Here's my problem - I would like to create an application, in a remote
> location to the main database server that displays the database
> contents. This applications would need to update its view of the
> database as soon as the database changes in order to ensure that only
> the most up to date information is being displayed.
>
> I've previously done this by periodically re-reading the database and
> updating the fields that have changed on screen, however as I add more
> terminals, this may cause a problem. So ideally I would like a
> callback or trigger to be called when the database updates that
> informs the correct client, so that it can update it's screen
> accordingly.
>
> Is this possible, or am I barking up the wrong tree? Is there a better
> way of doing it? I'd be very grateful if you could give me your
> thoughts.
>
> I am developing the main client application in C#, and the database is
> currently MySQL. It would be possible to change the database if this
> made things easier, however it would have to be a free alternative!
>
> Many thanks
>
> Steve
>

Thanks for the information. Initially there are only likely to be
about 1000 rows in the table that need to be fetched, and only by a
small (approx 10) clients or so. These will need to checked every 1/2
second or so, in order for the user to updated on activity. Pulling
the database contents at regular intervals may be possible at the
moment, but it likely that the database will grow in the future, so I
was looking for a good scalable solution.