Hi,

I'm developing two Qt based apps. Both of them rely on a local SQLITE database. The database is included in my installation package and everything works just fine. My problem is that the database includes a fair amount of data that will be generated by the users. How do I make sure to preserve the database when the users perform an 'upgrade' to newer versions of the apps?

I have looked into the postinst, preinst, prerm and postrm scripts and their documentations in: http://www.debian.org/doc/debian-pol...erscripts.html. Unfortunately, I still haven't figured out how to make use of them.

Another related problem is that with new version of my app, the structure of the database (tables and columns) as well as the default data (the rows) might get changed. I'd have to run 'upgrade scripts' on the users existing Db. Is there any best practice here? I can think of several approaches:

1. My app includes, in code, the necessary SQL statements to perform the upgrade.
2. I provide some script file which will upgrade the database.
3. Before the upgrade of the app, I do an 'export' of the user configurable data which I subsequently import back into the new database delivered with the new version (catering for any structural changes).

One of the apps also has some files (stylesheets to make the UI somewhat user configurable). I want to be able to preserve them as well. Anyway, the solution would be the same.

Db and files all reside in an .appname folder.

Any ideas?

Regards,

Magnus