This seems like it may be quite a straightforward query for experienced XQuery people - so forgive me if so. However, I am very much a novice when it comes to XQuery and am having trouble pulling out the information I need.
Basically, I have a large repository of XML files, each of which contains information about a particular book. Each file has an ISBN tag (<isbn>), and some, but not all, files also have a <copyright> tag, giving info about its copyright status.
I want to run an XQuery that searches for all files that include a copyright tag, and then for these files return bot