If I understand correctly "title" is a required Drupal field. The following don't have an obvious way to capture a title (from mods:mods/mods:titleInfo/mods:title or dc:title).
XQuery to generate the list
/metadata[not(resource_metadata/mods:mods/mods:titleInfo/mods:title) and not(resource_metadata/oai_dc:dc/dc:title) and not(resource_metadata/mods:modsCollection)]/@pid/data()
If I understand correctly "title" is a required Drupal field. The following don't have an obvious way to capture a title (from mods:mods/mods:titleInfo/mods:title or dc:title).
XQuery to generate the list