CODEWITHSUNDEEP
lucene
Yevgen Fesenko
Yevgen Fesenko

Reputation: 177

Lucene.net GetFieldQuery vs TermQuery

Using Lucene's standard analyzer. Title field in question is non-stored, analyzed. The query is as follows:

title:"Some-Url-Friendly-Title"

In Luke, this query gets correctly re-written as:

title:"some url friendly title" (- replaced by whitespace, everything lowercased).

I thought the Lucene.net version would be:

new TermQuery(new Term("title","Some-Url-Friendly-Title"))

However, no results are returned.

Then I tried:

_parser.GetFieldQuery("title","Some-Url-Friendly-Title")

And it worked as expected!

Both queries were executed via: _searcher.Search([query object], [sort object])

Can somebody point me in the right direction to see what the differences between TermQuery and _parser.GetFieldQuery() are?

Upvotes: 1

Views: 1365

Answers (2)

Bob
Bob

Reputation: 785

In Lucene.Net version 3.0.3 the GetFieldQuery is inaccessible due to it's protection modifier. Use 

MultiFieldQueryParser.Parse(searchText, field)

instead.

Upvotes: 0

femtoRgon
femtoRgon

Reputation: 33341

A TermQuery is much simpler than running a query through a queryparser. Not only is it not lowercased, and doesn't understand to break up hyphenated terms, it isn't even tokenized. It just searches for the term you tell it to look for. That means it is looking for the term "Some-Url-Friendly-Title" as a single untokenized keyword, in your index. I assume you are using an analyzer, so chances are no such tokens exist.

To take it a step further, if you had been searching for "Some Url Friendly Title" as the Term text, you still wouldn't come up with anything, since it's looking for "Some Url Friendly Title" as a Single Token, not as the four tokens (or rather, terms) in your index.

If you look at what a the standard query parser generates when you parse your query, you'll see that TermQueries are only one of the building blocks it uses to generate the complete query, along with BooleanQuery, and possibly PhraseQuery, PrefixQueriy, etc.

Upvotes: 2

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