Lucene - Query Programming


Advertisements


We have seen in previous chapter Lucene - Search Operation, Lucene uses IndexSearcher to make searches and it uses the Query object created by QueryParser as the input. In this chapter, we are going to discuss various types of Query objects and the different ways to create them programmatically. Creating different types of Query object gives control on the kind of search to be made.

Consider a case of Advanced Search, provided by many applications where users are given multiple options to confine the search results. By Query programming, we can achieve the same very easily.

Following is the list of Query types that we'll discuss in due course.

S.No. Class & Description
1 TermQuery

This class acts as a core component which creates/updates indexes during the indexing process.

2 TermRangeQuery

TermRangeQuery is used when a range of textual terms are to be searched.

3 PrefixQuery

PrefixQuery is used to match documents whose index starts with a specified string.

4 BooleanQuery

BooleanQuery is used to search documents which are result of multiple queries using AND, OR or NOT operators.

5 PhraseQuery

Phrase query is used to search documents which contain a particular sequence of terms.

6 WildCardQuery

WildcardQuery is used to search documents using wildcards like '*' for any character sequence,? matching a single character.

7 FuzzyQuery

FuzzyQuery is used to search documents using fuzzy implementation that is an approximate search based on the edit distance algorithm.

8 MatchAllDocsQuery

MatchAllDocsQuery as the name suggests matches all the documents.



Advertisements