XQuery questions

[bsneddon]

Sorry cross post but no one answered my question on
comp.language.python.

I am a little confused about XQuery.
I have read the tutorial on W3Schools site. It looks very powerful
and like
something I would like to use. The syntax doc("books.xml") from
W2Scools site looks like it might be related to
dom. I have read it is implemented in Saxon.
I have seen several post related to Berkley DB XML 2. Is it related
to a
database implementation and not just normal valid XML?

Does anyone know of a module for Python XML that includes XQuery?
It seem like it would be very useful. Is there a down side to XQuery
that has prevented it from being incorporated into some of the Python
XML offerings?
I have googled this some and have not seen answer to my above
questions.

Sorry if these seam like really dumb question. I do believe my
ignorance is curable.

Bill

 

[Joe Kesselman]

I have seen several post related to Berkley DB XML 2. Is it related
to a
database implementation and not just normal valid XML?

No. XQuery operates against an XML document. It doesn't even require
that the document be valid, though it can do more with a validated
document -- much of XQuery will work just fine against a document that
is merely well-formed.

Databases which have XML-specific support -- such as IBM's latest
version of DB2 -- may be expected to implement XQuery because it's a
better query language for XML than SQL would be. But stand-along
implementations also exist.

Is there a down side to XQuery
that has prevented it from being incorporated into some of the Python
XML offerings?

No. The real answer is that XQuery is a relatively recent standard, and
a complex one, so implementations are still relatively uncommon. (In
exactly the same way, XSLT 2.0, which became a Recommendation at the
same time XQuery did and which in fact shares a great deal of XQuery's
semantics, is also still relatively rare; XSLT 1.0 implementations are
much more common.)

I don't do Python, so I can't comment upon availability in that
language/environment.