First of all, we need to clarify some terminology here: there is no such thing as a "null date" in solr -- or for that matter, there is no such thing as a "full value" in any field. documents either have some value(s) for a field, or they do not hvae any values.
If you want to constrain your query to only documents that have a value in a field, you can use something like fq=field_name:[* TO *] ... if you want to constraint your query to only documents that do *NOT* have a value in a field, you can use fq=-field_name:[* TO *] Now, having said that, like Erick, i'm a little confused by your question -- it's not clear if what you really want to do is: a) change the set of documents returned in the main result list b) change the set of documents considered when generating facet counts (w/o changing the main result list) c) return an additional count of documents that are in the main result list, but are not in the facet counts because they do not have the field being faceted on. My best guess is that you are asking about "c" based on your last sentence... : get is 3 results and 7 non-null validToDate facets. And as I write this, : I start to wonder if this is possible at all as the facets are dependent : on the result set and that this might be better to handle in the : application layer by just extracting 10-7=3... ...subtracting the sum of all constraint counts from your range facet from the total number of documents found won't neccessarily tell you the number of documents that have no value in the field you are faceting on -- because documents may have values out side the range of your start/end. Depending on what exactly it is you are looking for, you might find the "facet.range.other=all" param useful, as it will return things like the "between" counts (summing up all the docs between start->end) as well as the "before" and "after" counts. But if you really just want to know "how many docs have no value for my validToDate field?" you can get that very explicitly and easily using facet.query=-validToDate:[* TO *] : <code><str name="facet">true</str><str : name="f.validToDate.facet.range.start">NOW/DAYS-4MONTHS</str><str : name="facet.mincount">1</str><str name="q">(*:*)</str><arr : name="facet.range"><str>validToDate</str></arr><str : name="facet.range.end">NOW/DAY+1DAY</str><str : name="facet.range.gap">+1MONTH</str></code> : : <result name="response" numFound="10" start="0"><lst : name="facet_counts"><lst name="facet_ranges"> <lst name="validToDate"> : <lst name="counts"> <int name="2011-11-14T00:00:00Z">7</int> -Hoss
