[Xapian-discuss] Simulating Fields

[Luis Alberto Zarrabeitia Gomez]

Quoting Olly Betts <olly at survex.com>:

> On Sun, May 03, 2009 at 10:04:03PM -0400, Luis Alberto Zarrabeitia Gomez
> wrote:
> > 
> > Quoting James Aylett <james-xapian at tartarus.org>:
> > 
> > > You can use the QueryParser for this; set a term prefix before parsing
> > > the query, for instance.
> > 
> > I tried to do this (qp is a QueryParser instance, with the same stemmer)
> > 
> > ===
> >   qp.set_stemming_strategy(xapian.QueryParser.STEM_SOME)
> >   qp.add_boolean_prefix("realtitle",'XTITLE')
> >   qp.add_prefix("title","XTITLE")
> > ===
> 
> I'm not sure what you think "realtitle" is going to be useful for.  It
> doesn't generally make sense to have the same term prefix generated by
> both boolean and probabilistic prefixes.

Neither do I :D. I was trying to experiment which kind of prefix would help
me... and as the probabilistic query wasn't working (see below), I tried a
boolean one.

 
> If you want a phrase, the syntax is double quotes:
> 
> title:"Sex and the City"
> 
> If you want to apply the prefix to all terms in a subexpression, use
> brackets:
> 
> title:(Sex and the City)
> 
> Note that the syntax supported by the QueryParser is described here:
> 
> http://xapian.org/docs/queryparser.html

Ohhh. I didn't know that. I hadn't found that page. Thanks!.

Now, what would you recommend to match the document titled "sex and the city",
but not "sex and the city 2: the return"? Adding a value to the document and
then checking it for the documents in the result set?

> > Could you provide me an example?
> 
>     document.add_term("XTITLE" + page.title)
> 
> I'm not sure I'd recommend this approach though - there's a limit of
> about 240 bytes on the length of terms.

Good to know!

Thanks.

-- 
Luis Zarrabeitia
Facultad de Matemática y Computación, UH
http://profesores.matcom.uh.cu/~kyrie


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