CODEWITHSUNDEEP
lucenelucene.netwildcard
user57175
user57175

Reputation: 3434

Leading wildcard character throws error in Lucene.NET

If the search query contains a leading wildcard character (* or ?), the QueryParser's Parse function throws an error.

Dim q As String = "*abc"
Dim qp As New QueryParser("text", New StandardAnalyzer())
Dim query As Query = qp.Parse(q)

Is there any way to solve this problem in Lucene.NET v2.0.0.4?

Upvotes: 4

Views: 4081

Answers (3)

Ondrej Bozek
Ondrej Bozek

Reputation: 11501

You can avoid wildcard queries by utilizing NGramFilter for your index analyzer. Than you have to use search_analyzer without NGramFilter. This way you can search similar to like "%text%" without even needing wildcards. You just enter 'abc' and your index would be searched for all entries containing 'abc' very quickly.

Upvotes: 0

Kai Chan
Kai Chan

Reputation: 2473

Set QueryParser.SetAllowLeadingWildcard Method to true. The API page states that "this can produce very slow queries on big indexes" though.

Upvotes: 5

Xn0vv3r
Xn0vv3r

Reputation: 18184

Maybe you have to use a WildcardQuery, but

...In order to prevent extremely slow WildcardQueries, a Wildcard term should not start with one of the wildcards...

Upvotes: 1

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