pcplantdb

[Richard Morris <webmaster@pfaf.org>]

Lawrence F. London, Jr. wrote:
> John Schinnerer wrote:
>
> > IMO an XML DTD will be a part of formal specs - specifically, it will 
> > be the spec for XML markup to be used however we end up using XML 
> > markup in the project.
>
>
> What is a DTD
> And what is a schema (scheme, simply put?)

A DTD stands for Document Type Definition (or something like that)
they are used to specify whats allowed in an XML document and specify 
how it should be structured.

For example a DTD for HTML would list the allowed tags <p>, <b>, <h1> 
etc and where they could appear.

An XML Schema does a similar job, but has a slightly different emphesis.
Advantages are
    * XML Schemas are extensible to future additions
    * XML Schemas are richer and more useful than DTDs
    * XML Schemas are written in XML
    * XML Schemas support data types
    * XML Schemas support namespaces
(stolen from http://www.w3schools.com/schema/schema_intro.asp)

You also get Schema for databases which describe the structure of a 
database, i.e. the tables and fields in the tables.

Rich