I understand that it would be best to have a UI that mapped lists of terms to MUST, MUST_NOT and SHOULD, but I'm currently constrained to using the QueryParser with boolean operators.
Given that, I was thinking that the addition of "*:*" (in 2.1) to represent MatchAllDocsQuery might help solve:
" NOT Chair " is the problem ... you can't have a negative clause in isolation by itself -- it doesn't make sense because there isn't anything positively selecting results for you to then exclude results from. by making that: "*:* NOT Chair"
To test, I indexed these documents: *DocID* *Body Value* 0 A B C 1 A B C D 2 A C D 3 B C D 4 C D 5 B Searching in Luke, here's what I see: *Query* *Parsed As* *Expected Matches* *Actual Matches* NOT B -body:B 2, 4 <none> *:* NOT B MatchAllDocsQuery -body:B 2, 4 2, 4, 5 *.* AND NOT B +MatchAllDocsQuery -body:B 2, 4 2, 4, 5 Can someone explain why doc 5 is matched for both "*:* NOT B" and "*.* AND NOT B"? Are my Expected Matches incorrect? Thanks, david On 11/3/06, Chris Hostetter <[EMAIL PROTECTED]> wrote:
: When I enter the query: "Table AND NOT Chair" I get one hit, doc3 : When I enter the query: "Table AND (NOT Chair)" I get 0 hits. : : I had thought that both queries would return the same results. Is this a : bug, or, am I not understanding the query language correctly? it's a confusing eccentricity of the QueryParser syntax ... as a general rule, thing in parens need to be self contained, effective, queries ... if you have something in parens which would not make sense as a query by itself, then it won't make any more sense as part of a larger query. In your case, the query " NOT Chair " is the problem ... you can't have a negative clause in isolation by itself -- it doesn't make sense because there isn't anything positively selecting results for you to then exclude results from. As a side not: i strongly encourage you to train yourself to think in terms of MUST, MUST_NOT and SHOULD (which are represented in the query parser as the prefixes "+", "-" and the default) instead of in terms of AND, OR, and NOT ... Lucene's BooleanQuery (and thus Lucene's QueryParser) is not a strict Boolean Logic system, so it's best not to try and think of it like one. -Hoss --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
