How to search for documents that have a list property empty ?
Like documents having no value in the dc:subjects field.
You can use the following query for this:
SELECT * FROM Document WHERE dc:subjects/* IS NULL
Adding the usual filters on deleted documents or versions:
SELECT * FROM Document WHERE dc:subjects/* IS NULL AND ecm:mixinType != 'HiddenInNavigation' AND ecm:isCheckedInVersion = 0 AND ecm:currentLifeCycleState != 'deleted'
If the question is about the User Interface and the default forms displayed by Nuxeo (in the FacetedSearch for example), then you must override the search or add you own (Content-View in Studio, with the “Faceted Search” box checked), because by default, Nuxeo handles the empty parameters of these layouts as if they where not filled at all.
You mught consider adding this case to the documentation page :
So give me the documents that have subject X or no subject at all.