I'm working on implementing search functionality on a website, and I'm using Solr for this. Everything works fine, but I've got a little trouble with the facet.missing parameter for a field.
The field may have the values A, C or simply just null
. That is, the field is present on all documents, but when there is no value then the value is null
.
With regards to the facet.missing parameter, the documentation says "[...] a count of all matching results which have no value for the field [...].". However, what does "no value" mean? Does it mean that the field is not present on the document at all? Does it consider null
, an empty string and/or something else to be "no value"?
As it is right now, null
does not seem to be a "no value" as facet.missing does not exclude the count for documents where the field value is null
. However, I'd like to hear if someone has more insight on this?