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From "Terry Steichen" <te...@net-frame.com>
Subject Re: Keyword search with space and wildcard
Date Fri, 29 Aug 2003 16:02:16 GMT
Tatu,

I agree.  One problem, however, that new (and not-so-new) Lucene users face
is a learning curve when they want to get past the simplest and most obvious
uses of Lucene.  For example, I don't think any of the docs mention the fact
that you can't combine a phrase and a wildcard query.  Other things that are
obviously quite well understood by many members of the list, are still
less-than-clear to others.  For example, I found (and still find) it a bit
difficult to find concrete examples/advice of how to get good benefit from
filters.

My whole point is that this is a *very* powerful and flexible technology.
But I think it's often very difficult for those most experienced in using
Lucene to fully appreciate how it looks from the "newbie" point of view.

Just my $0.02.

Regards,

Terry


----- Original Message -----
From: "Tatu Saloranta" <tatu@hypermall.net>
To: "Lucene Users List" <lucene-user@jakarta.apache.org>
Sent: Friday, August 29, 2003 11:14 AM
Subject: Re: Keyword search with space and wildcard


> On Thursday 28 August 2003 21:54, Brian Campbell wrote:
> > Basically, yes, I am trying to put a wildcard in a phrase.  My field (a
> > Keyword) is the name of a project.  It can be 40 characters long (I'm
> > basically indexing some database columns).  Since it is a Keyword and
not a
> > Text field, it doesn't get tokenized (I do this on purpose) and must
match
> > up exactly.  I would like for users to be able to search on partial
phrases
> > such as "Hello w*" and match up to "Hello world" and "Hello washington",
> > etc.  Is this not possible?  Is it documented anywhere?
>
> This can be done, AFAIK.
>
> This is one thing that many people seem unaware of: you don't HAVE to use
> QueryParser to build queries. In your case it seems like you should be
able
> to construct query you want if you either by-pass QueryParser, or create
> a dummy analyzer (one that does no tokenization but returns all input as
> one token).
>
> Since QueryParser is fairly simple class, you should be able to see how
wild
> card queries are constructed. You can not (and need not) create a phrase
> query since it does not allow wild cards (like someone pointed out), but
> since the whole phrase is just one token for keyword fields, you can use
> normal wild card query (or prefix for cases like "Hello w*").
>
> It would be nice if FAQ could point out that QueryParser is higher-level
> interface to query part, but it is possible and sometimes necessary to do
> your own query construction. I think it's very cool Lucene queries were
> properly modularized this way -- too many open source projects have
> components too tightly coupled.
>
> -+ Tatu +-
>
>
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