Removing the case element from the schema
While working on the import process to bring the XML data into the website database, it occurred to me that, after all of the changes to the schema, the <case> element doesn't serve much of a function anymore. While it used to group together multiple trial files, all of the useful grouping information (namely the trial dates) has been moved to the <trial_file> elements themselves. So, we don't need the extra level in the hierarchy.
For that matter, we also don't need the <regular_cases> element that wraps up the <case> elements, since it's also an extra level of hierarchy. The schema really just needs to be: data -> one or more trial files
Thus, I've removed <regular_cases> <case> from the schema and modified the XSLT transformation scripts accordingly. I also modified the data that's already been processed.
These changes will make the PHP script that converts the XML to MySQL simpler.