Hi Dmitry,
On Mon, 2007-04-23 at 11:20 +0300, Dmitry Turin wrote:
> >I would change your examples to use less abstract
> > data, like department/employee, customer/product/order/order_line
>
> This will not help.
> To my mind, forum of real database is place,
"What we got here is ... failure to communicate."
I may be wrong, but I suspect most of the people in this forum take a
look at
create table a ( id num primary key; data float;
);
create table b ( id num primary key; ref num references a(id); data float;
);
create table c ( id num primary key; link num references b(id); data float;
);
or even
create table a ( id integer primary key, data float);
create table b ( id integer primary key, ref integer references a(id), data float);
create table c ( id integer primary key, link integer references b(id), data float);
and your attempts to derive XML from them and ask questions like "how
will this help me in my day-to-day job" and "what do a, b and c
represent or are analogous to?" and all they'll see is a hierarchy of
some sort (as evident by several of the responses) and they'll dismiss
it because they have to deal with more complex relationships and the
relational model allows them to express such connections.
OTOH, if you were to take a real-life example, and show you can generate
XML from your proposed TML, I contend that then you'd find more people
receptive to your ideas or at least able to criticize them from more
concrete viewpoints.
Take a look for example at Philip Greenspun's "SQL for Web Nerds". It's
dated and its examples are based on Oracle syntax, but it's based on a
real web application. Show us what TML can do for the users, bboard and
classified_ads tables
(http://philip.greenspun.com/sql/data-modeling.html), and how it can
answer the simple and complex queries in the next two chapters (or as I
said, pick a real-life example of your own) and then maybe we'll have a
more fruitful conversation.
Joe
