lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Ivan GuÅūvinec <>
Subject Re: Field searching for nothing
Date Sat, 09 Apr 2005 13:12:24 GMT
I believe there isn't. I don't think any of the existing QueryParsers 
implements "search empty field" expression.

The way you might solve this requirement is to use a special "empty term" 
for such fields. For instance, I use single underscore "_" as a value for 
all empty fields in the document. I also use Keyword field to store this 
value verbatim (avoid Analyser that might not want to index a single 

Searching for "empty term" can then be performed programmaticaly with a 
indexSearcher.Search(new TermQuery(new Term("author", "_")));

General guide for the "empty term" value would be to choose a term that does 
not occur in any text you put into your index.

On Apr 9, 2005 12:44 AM, Bruce Best (CRO) <> wrote:
> Is there any syntax to find all the documents where a particular
> Lucene-indexed field is empty?
> For instance, say there is a field called "author". I can do a field 
> for
> author:cutting
> to find all documents with "cutting" in the author field; I could also
> search for
> author:"*"
> which would return all documents, whether there was something in the 
> field or not.
> What if I wanted to find all those documents that had nothing at all in 
> "author" field? I tried a few combinations of wildcards and other various
> Lucene symbols, but they generally resulted in errors.
> Is it possible with Lucene to specify "Return all documents where fieldx: 
> empty"?
> Thanks,
> B.
> ---------------------------------------------------------------------
> To unsubscribe, e-mail:
> For additional commands, e-mail:

  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message