GML Examples
================

This directory contains sql scripts which show, by example, how to use
the GML features of Spatial DataBlade.  You can run any of these 
scripts using a SQL editor such as DB-Access, or SQLEditor on NT clients.

Note: DB-Access ignores formatting characters inserted in the result, 
  instead it inserts a newline after each 65 output characters. This 
  algorithm clashes with the way SE_AsGML() outputs text, and the results 
  may look garbled.


XML Validation
----------------
  Without proper headers/trailing tags, the SE_AsGML() UDR does not produce 
  an XML document, but just a fragment.  An element in a well-formed XML 
  document that contains SE_AsGML() output should have attributes that
  relate to the GML schema and other extension schema documents if 
  applicable.  You may validate the document using a schema-aware parser. 
  
  The file se_asgml.xml contains GML fragments embedded in a <document>
  element.  Here is how to use Apache Xerces-J.1.4.1 to validate this 
  se_asgml.xml (make sure the files xerces.jar and xercesSamples.jar are in 
  your CLASSPATH):

  java dom.DOMCount -v se_asgml.xml

Note: the validation will generate the following error message:

  'The error 'Element type "document" must be declared.'

  This happens because a "document" element that is not defined elsewhere
  is used to enclose all the GML fragments. In a real application, it will 
  be replaced by an application-defined element.