There's really not a clean (straightforward) way to do this.
You can probably find some creative ways around it, though. Some might include:
1. if you're using -S prog, use some standard string to indicate no value for a
property: NA or NONE or something like that. Some string that won't be likely to
appear in valid properties.
2. search for (not a*) and (not b*) ... and (not z*)
for each of your word characters (start word characters, really). You could set
that up as a pre-defined query. I would expect it to be really slow
(comparatively) though, because of all the wildcards.
3. Like #1, but use a low ascii char (a control character) to indicate the
'empty' property. Then set PropertyNamesNoStripChars config param to 'yes'.
CheHax scribbled on 6/3/05 5:16 AM:
> Hello list,
> I am still working on my search engine (it is working pretty smoothly
> now and should be open in beta) and I was wondering if there is a way
> to search for an empty metatag.
> Say I have 2 metas : company name and company activity.
> I want to search companies with undefined activity, and so an empty string...
> Is there a way to do so ?
Peter Karman . http://peknet.com/ . peter(at)not-real.peknet.com
Received on Fri Jun 3 06:39:20 2005