Re: XML-Relational Mapping (Was: USQL)

[Brian McCallister]

it seems to me the embedded Xindice option should work pretty 
painlessly for most simple persistence needs. If it is hard to use, the 
better option may be to look at how to make it easier to use. If an XML 
-> rdmbs automapper and schema generator is needed it seems a lot like 
reinventing a new backend for an xml database.

-Brian

On Feb 24, 2004, at 10:21 PM, roy huang wrote:

It sounds good.I think many application just use very simple 
database,I saw application just use one or two table for data storage 
only.
If we(beginners ;)) can just using mapping to combine xml and database 
for select/add/update/delete,life is much easier with cocoon.
+1

Roy Huang
----- Original Message -----
From: "Daniel Fagerstrom" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, February 24, 2004 9:06 PM
Subject: XML-Relational Mapping (Was: USQL)

Reinhard Poetz wrote:
...
It would be very cool if we could provide something that helps with 
flow
applications. I like the combination of OR-Mapping/CForms/Flow but 
this
is for many beginners overkill. They shouldn't be forced to write 
Java
code e.g. in order to implement a simple register form.

--
Reinhard
I think it is overkill for many non beginners as well ;)

I am currently looking at XML-DBMS 2.0,
http://www.rpbourret.com/xmldbms/index.htm, which is an XML/relational
mapping tool. The main idea is that you describe the mapping between 
XML
and the relational db in a mapping file, then you can use the mapping
tool to both store the XML document in the db and retrive XML from the
db. The detailed storing strategy - using overwrite or update etc can 
be
fine tuned in another configuration file. And the retrieving behaviour
can fine tuned with a filter file.

XML-DBMS is intended for data centric rather than document centric
applications and provide a rather flexible mapping between one XML
document and a number of tables. It also contains a tool for 
generating
maping files from DTD:s and, IIUC, from db meta data. It can also
generate create table statements from the maping file.

I think XML_DBMS look rather promissing, and I have not found any 
other
packages that dom direct XML relational mapping, all other seem to
require Java objects in the middle. Anyone that know about any 
simmilar
packages?

Possible drawbacks are that the community is very small, and that the
packaging is not that good: no ant script. The documentation is good
however, Ronald Bourret, the main author have written a number of
articles about XML mappings.
 The licence is: "XML-DBMS, along with its source code, is freely
available for use in both commercial and non-commercial settings. It 
is
not copyrighted and has *absolutely no warranty*. Use it as you will."

Given that XML-DBMS holds what it promise, I will try to build an 
block
around it. My idea is to use XML-DBMS from flowscripts, so the best 
way
to integrate it would probably be to write some component, like
pipelineUtil around XML-DBMS. An SQLToXMLTransformer 
XMLToSQLTransformer
pair would also be a possibility.

Others interested in such a block? Opinions?

/Daniel