Levenshtein algorithm for closeness matching.Īggregates other Query instances into complex expressions allowing AND, OR, and NOT logic.Īll of these Query implementations are in the package. Matches all terms that begin with a specified string. Lightweight, regular-expression-like term-matching syntax. Matches documents with terms between beginning and ending terms, including or excluding the end points. Single term query, which effectively is a single word.Ī match of several terms in order, or in near vicinity to one another. The relevant subclasses, their purpose, and some example expressions for each are listed in the following table: We need some understanding of the underlying concrete Query subclasses. When a human-readable query is parsed by Lucene’s QueryParser, it is converted to a single concrete subclass of the Query class. For example DateTime: ModificationDate:>’ 12:00:00′ We will explain searching operations on these fields in a later section. There are a few special field types that have their own syntax for defining the query term. Any existing field name can be used as field name. Then there’s BooleanQuery, PhraseQuery, and many other Query subclasses to choose from.įields When performing a search we can specify the field you want to search in. With Lucene Java, TermQuery is the most primitive Query. Multiple terms can be combined together with Boolean operators to form a more complex query. A Phrase is a group of words surrounded by double quotes such as “welcome lucene”. A Single Term is a single word such as “test” or “sample”. Terms are of two types: 1.Single Terms and 2.Phrases. A query is broken up into terms and operators. Lucene has a custom query syntax for querying its indexes. In this chapter we will talk about the Lucene queries. We also have built up a small search application using lucene indexing & searching procedures.
In a previous chapter we have learned the different components of the Lucene search engine. Table Of Contents 1.Introduction 2.Lucene Queries 3.Lucene Query API 4.Basic search 4.1.Terms 4.2.WildcardQuery 4.3.Boolean Operators 4.3.Grouping 4.4.PhraseQuery 4.5.RangeQuery 4.6.Prefix Query 4.7.Fuzzy Query 1.Introduction
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