[jdom-interest] SQL join -> Structured XML

[Shaun Smith]

I think the important thing about Philippe's classes is that
it deduplicates records to actually provide a hierarchical view
of the joined resultset.  I have found this approach incredibly
useful, especially when the required dataset has grown large.
Phillipe, you may also be interested to try straight traversal
of the database to producte the results - this may actually
be faster.

For instance, in a one to many relationship, the tabular result
will include the one record as many times as there are many records.
This can be quite wasteful to process.

Microsoft do have a technology called ADO Shape which allows hierarchical
queries to be submitted, although I have not actually used it myself
it does look great.

Shaun.

> These classes are useful for reporting, not exactly for 
> search. We send a query with joins to the database, get back 
> a tabular result (CachedRowSet), create a structured XML file 
> from this result, and sent it to FOP, which can ouput PDF, 
> PCL, PS... The classes do not generate code.
> 
> Is there another way to get XML from a database query with 
> joins? I know some databases can actually give back XML 
> directly, instead of a tabular result, but this is not a 
> feature we can rely on. It's not portable enough.
>