ORing complementary queries gives no results

["Satuluri, Venu_Madhav" <Ve...@deshaw.com>]

Hi all,

I build Query objects programmatically. I do this by getting a
TermQuery/PhraseQuery/whatever for each term in the user query, make a
BooleanClause by specifying isRequired and isProhibited depending on
whether the term has an "and" or an "or" or an "or not" etc prefixed
before it (I use 1.4.3, which is why I use isRequired, isProhibited
instead of BooleanClause.OCCUR). I combine all the BooleanClauses in the
end to get my final Query.

This is working fine, except for one case where I ORed two complementary
queries, i.e. I searched for "name:xyz or -name:xyz". Both of these
queries independently produce results but both joined together don't.
The isRequired parameter is false for both the parts of the query, while
isProhibited is true for the second and false for the first. Shouldn't
this query return all the documents which have some value of the field
"name"?

Thanks,
Venu

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Re: ORing complementary queries gives no results

[Chris Hostetter <ho...@fucit.org>]

I suspect the final query structure isn't what you think it is ... take a
look at the toString on your query.

in general, there is no way to just do a "NOT foo" type query ...
prohibiting things only makes sense in the context of selecting something
else ... i'm guessing the query structure you acctually have is...

	name:xyz -name:xyz

...which means positively select anything matching name:xyz and then
prohibit anything matching name:xyz ... hence the empty set.

if you truely want a "NOT foo" style clause which you can then combine
with other queries in a true boolean set fashion, you'll need to use a
MatchAllDocs query or soemthing like it...

       name:xyz (field_every_doc_has_set_to_true:true -name:xyz)



: Date: Tue, 23 May 2006 14:47:32 +0530
: From: "Satuluri, Venu_Madhav" <Ve...@deshaw.com>
: Reply-To: java-user@lucene.apache.org
: To: java-user@lucene.apache.org
: Subject: ORing complementary queries gives no results
:
: Hi all,
:
: I build Query objects programmatically. I do this by getting a
: TermQuery/PhraseQuery/whatever for each term in the user query, make a
: BooleanClause by specifying isRequired and isProhibited depending on
: whether the term has an "and" or an "or" or an "or not" etc prefixed
: before it (I use 1.4.3, which is why I use isRequired, isProhibited
: instead of BooleanClause.OCCUR). I combine all the BooleanClauses in the
: end to get my final Query.
:
: This is working fine, except for one case where I ORed two complementary
: queries, i.e. I searched for "name:xyz or -name:xyz". Both of these
: queries independently produce results but both joined together don't.
: The isRequired parameter is false for both the parts of the query, while
: isProhibited is true for the second and false for the first. Shouldn't
: this query return all the documents which have some value of the field
: "name"?
:
: Thanks,
: Venu
:
: ---------------------------------------------------------------------
: To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
: For additional commands, e-mail: java-user-help@lucene.apache.org
:



-Hoss


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