XML

Please search the archives and then direct these sorts of questions to the
pgsql-general list. This list relates to the development of PostgreSQL.

Gavin

On Fri, 15 Mar 2002, longjohn wrote:

If it's a servlet calling the database in your example, the below can
be accomplished through the use of procedures which create the XML in
question and return it.

Ie. select xmlGetUser(userid);

You have to write xmlGetUser() to take in the userid and return the
xml required for it. I see no advantage to generating the xml in the
db rather than in the servlet.

Soap or XML-RPC on the other hand could be a useful tool for the
database to understand directly -- but thats certainly not going to be
fast.
--
Rod Taylor

This message represents the official view of the voices in my head

----- Original Message -----
From: "longjohn" <longjohn@katamail.com>
To: <pgsql-hackers@postgresql.org>
Sent: Friday, March 15, 2002 8:44 AM
Subject: [HACKERS] XML

Do U know if pgSQL supports XML ?
4 example : BROWSER->APACHE JSERV->SERVLET->DB->xsl+xml->HTML
Do U know any open source DB doing that?
Thanks a lot

---------------------------(end of

broadcast)---------------------------

On Fri, 2002-03-15 at 15:44, longjohn wrote:

Do U know if pgSQL supports XML ?
4 example : BROWSER->APACHE JSERV->SERVLET->DB->xsl+xml->HTML

Not natively, you need extra tier that will do (DB->xml)

Do U know any open source DB doing that?

Check http://dmoz.org/Computers/Software/Databases/XML/

--------------
Hannu

On Fri, 15 Mar 2002, longjohn wrote:

Do U know if pgSQL supports XML ?
4 example : BROWSER->APACHE JSERV->SERVLET->DB->xsl+xml->HTML

There's some xml stuff in the contrib directory of the PostgreSQL
distribution.

Vince.
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You have to write xmlGetUser() to take in the userid and return the
xml required for it. I see no advantage to generating the xml in the
db rather than in the servlet.

As a counterexample, my PKIX extensions defined an "XML" datatype
that could be used to generate XML instead of the standard format.
E.g.,

select cert as xml from certs where ....;

But this was an exceptional case - for many of the objects the
"standard" format is a base-64 encoded ASN.1 string, but with
XML I need to extract the fields *and* still include the object
as a base-64 encoded ASN.1 string. It was *much* easier to just
generate it in the backend than to do it at the db->xml level.

More generally, I think we need to keep an mind an important
distinction here. Most of the time XML represents the contents
of an entire tuple, and each field corresponds to a attribute.
In these cases an external db->xml layer makes the most sense.

But with extensions it's common to have complex objects in a
single attribute, and there may be a standard way to represent
the object in XML. (E.g., all of my XML conversions are extracted
from the proposed "Signature" schema at W3C.) In these cases
it may make more sense for the extension to provide its own
XML mechanisms, but it would be nice if there was s standard
way of handling this.

My suggestion was mentioned above. Just make "xml" a standard
data type. It can be transparently converted to/from text, but
you can define functions that return "xml" (or accept xml) and
use casts to specify when you want XML instead of the normal
format for that attribute.

Hi,

I have something that do exactly what you are looking for (and more)
but damned it's perl stuff !

You just have to set your SQL queries into XML files, associate
XSL template to them and run a cgi perl script througth apache (with or
without mod_perl). You can also add perl procedures to process your data
before output. I also parse cgi parameters... and more.

If you're interested let me know !

longjohn wrote: