xml-dev - Re: XML Schema generation questions [was SQL schema to XML schema...]

[tpassin@home.com]

Mike Sharp  wrote, responding to a post of mine -
> <<<Therefore, it is natural - nearly mandatory - to represent a row as an
> element. >>>
>
> I suppose that if you wanted to represent the _schema_ of the database, it
would
> indeed be mandatory.  But if, rather, you were interested in the data for
it's
> own sake, you may want to represent it differently.  Relational databases
are
> limited to data in two dimensions--rows and columns.  They use the
relationships
> between tables to get the extra-dimensional aspects that real data has.
In my
> opinion, you shouldn't hamstring your XML into a two dimensional world.
Of
> course, if your goal is to simply pack the data in a database into XML for
> transport, then this approach would work.  But you need some more stuff
for the
> metadata such as this column is a foreign key into that table.

You could store the foreign key information in another table, like many
relational databases do.

>XML does providea mechanism for that, but I've never used it.
>

Yes, you are getting into the matter of where object models are stronger vs
relational models.  It's an interesting area.  I was just responding to a
question about representing tables (as I thought).  Object models for data
have a lot of useful features, but sometimes it seems like some things are
getting lost - things that have been learned painfully over the years.
Relational models are strong on letting you have new views of your data that
were not designed in at the start.  They are also strong in helping you
store a piece of data one time, in one place, which reduces update and
delete problems.

It's a great topic!

Cheers,

Tom Passin


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