WebService, Client, Server, DB, versioning....

[Martin]

Hey,

I am currently writing a WebService ("Server") and a WinApp ("Client")
so that a user can use a third program through the web. To do that
the client needs a table from a database.

Here is the setup:

1. WebService on the webserver
- Can access the DB directly because it is located on the same
machine.
- Provides the following methods for the client
1. get the entire table
2. change values in the table on the server
3. if a row on the server is newer that the currend row on
the client - get that row.

Now I did not have problems writing the first two methods but the
third seems to be hard because I have no idea how to compare the two
tables without causing a lot of traffic.
I thought about adding a field to the table or even a field to every
row in the table containing the date of the last change but I don't
think it is possible for me to change anything in the db.
Than I thought to use versioning of a DataSet but than the server
would need to be 'up' all the time and I would need a global DataSet
that holds that table all the time. That does not sound good.

Does anybody have an idea how my client could check if it's version of
the table is up to date?

Thank you

Martin
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