An example of database query result in XML

[Don Park]

>It's certainly interesting and instructive: I would never have thought of
>doing the metadata in quite that way.

Frankly, it looks pretty sick from certain perspective but thankfully the
feeling goes away after reading a stack of XML specs ;-)

>Is it really practical to have quite so much tagging? I know it will
>compress beautifully for transmission over a network, but compressing a
gigabyte
>file is not something one does just for fun. Using shorter tags (e.g. <c1>,
><c2> for the cells would be a simple fix, but it's still much bigger than a
CSV file.

Using shorthand tags is nice but losing clarity to save a few characters is
quite worth it especially if the loss will be propagated down the line (i.e
XSL rules will start to look funky).  I am perfectly willing to trust the
compression to do its magic at this point.

>I would be interested to know why you chose the representation
><row><col1>A</col1><col2>B</col2></row>
>rather than <row col1="A" col2="B"/>

1. I wanted to treat column and rows on equal footing so that you could have
columns on the outside as well as inside.
2. I do not like using attributes to hold contents.
3. Using #FIXED attribute values for field metadata will certainly not work
since there is no attributes for attributes.

My XDO example's main attraction is the way the metadata is described as
internal DTD subset.  The result can now be carried to any database and
inserted with very little ambiguity.

>One other minor comment, are you doing anything to preserve white space
>in the data content?

Yes.  Whitespaces in Field element content are significant.  For example,
the <ShipAddress> element content can have linefeed.

As I mentioned before, my XDO example is something anyone can write over a
weekend because extracting XML-based information from legacy systems is a
no-brainer.  Going the other direction is much harder and should be fertile
ground for quite a few startups.

XML is very flexible and it is easy to convert practically any data into XML
without significant loss of information.  But because XML is so powerful,
the problem of converting XML to other data formats is much greater than
before and is bound to cause information loss.  So I guess I am leading
toward using XML more as a data communication format and less as a data
storage format.

Just whining cuz I am not going to the XML Conference,

Don Park
http://www.docuverse.com/personal/index.html



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