Re: VisAD and SQL databases


Justin Clift wrote:

Ugo Taddei wrote:

The SQL query is DB-specific, and it makes no sense to create VisAD/SQL adapters. (In fact, it is impossible to write an adapter which will work with every JDBC-capable database.)

Wouldn't it be possible to at least put a JDBC framework in place, so that people could just plug in the appropriate JDBC driver for their database and ensure the queries that get written follow the conventions for their database?

Yes, it is possible.

Given that most JDBC drivers decently implement SQL standards, it should also be possible to give some pretty detailed *SQL conformant* examples by which to guide people too.

It might not necessarily make sense to try and make a solution that works "out of the box" for everyone, but it does seem possible to lay a lot of the groundwork in place so that people only need to do the final few steps.

Sure. To make it clear: an out-of-the-box, universal solution is not possible (unless we all agree on a common DB data model). But it is possible to simplify the work, so that people only need to provide a minimum of info (JDBC driver, db-url, user name, etc...).

Does that make sense for a VisAD context?

I'd say it depends on how big your project and your dataset are. For our stuff I opted for a one-off solution. Apart from variables (RealTypes) we had specific units and lots of other metadata stored in other tables.

Am not trying to argue pointlessly here btw, just suggest what sounds like a valuable extension to the VisAD featureset.

Absolutely! Adding SQL-capability is a nice thing and I could try to give some help. Actually, we're about to start a project based on PostGIS/PostgreSQL and would be happy to try to contribute to your effort.




Regards and best wishes,

Justin Clift