[
Lists Home |
Date Index |
Thread Index
]
** Reply to message from tblanchard@mac.com on Mon, 21 Oct 2002 11:12:38 +0200
> > Agreed! In fact, even well-architected desktop apps have a clear
> > separation of concerns between the user interface, the control logic
> > and the data. Today, it makes increasing sense to express that
> > separation using XML over sockets (rather than putting SQL in the UI).
> And this is better how? You swap one linear syntax over sockets for
> another linear syntax over sockets and this is supposed to make it
> elegant because its <genuflect>XML</genuflect>? These two approaches
> are fundamentally the same thing.
The two approaches may look the same, but looks can be deceiving. SQL queries
tend to be tightly coupled to a particular physical database schema, which makes
them brittle with regard to changes in the DB schema and/or changes of target
database. XML queries tend to be more declaritive in nature, with a receiving
system then mapping the queries to a database-specific request (which could be
SQL).
These are sweeping generalisations - if you run your SQL queries only on views,
or are only calling stored procedures, you do have decoupling from the physical
database schema. Equally, you can create XML query formats that are tightly
coupled to a particular physical database schema. That said, my experience is
that tight coupling is harder to avoid when you use SQL, simply because it is
harder to refuse the requests for direct access to the physical schema for
queries. This is a socio-political observation, rather than just a technical
one.
Cheers,
Tony.
====
Anthony B. Coates, Information & Software Architect
mailto:abcoates@TheOffice.net
MDDL Editor (Market Data Definition Language)
http://www.mddl.org/
|
