Re: [xml-dev] Re: [xquery-talk] JDBC in an XQuery world (?)

[Liam R E Quin <liam@w3.org>]

On Sun, 2011-10-02 at 14:42 -0400, John Cowan wrote:
> Liam R E Quin scripsit:
> 
> > > What if I have (or want) an XQuery database
> > > (or would you call that a XML database with an XQuery interface ...?) 
> > 
> > SQL/XML I think describes enough of a mapping, no?
> 
> I don't think so.  SQL/XML extends SQL to add XML as a new kind of primitive
> SQL data type, like strings, numbers, and dates.  What's needed here is a
> way to do ordinary SQL operations over an XDM-based database.

I saw David's first question as having two aspects - could you connect
to a remote XQuery database using ODBC/JDBC and send it XQuery
expressions... the answer is probably, given that SQL has an XQuery
function now.  The other aspect, could you map from the XDM into SQL
types, is also addressed by SQL/XML, as I understand it (e.g. how
xs:dateTime maps to SQL date) so that you can use the results... When we
published the XQuery 1.0 Recommendation we were careful to liaise
between the editor of the ISO SQL work and the (co-)chair of the W3C
XQuery work... which was a straightforward mapping also.

The other question is, could you provide something jdbc-like but with no
SQL at all, not even a one-line wrapper function, and return XDM
instances directly to a system that can deal with this.  Sure, and we
could probably define an xdm:// or xquery:// URI scheme too. Lots of
interesting possibilities.

Liam


-- 
Liam Quin - XML Activity Lead, W3C, http://www.w3.org/People/Quin/
Pictures from old books: http://fromoldbooks.org/