This page contains a phrase search definition as well as a phrase search description with use of GroupDocs.Search API.
Phrase search definition
Phrase search is a type of search that allows users to search for documents containing an exact sentence or phrase rather than containing a set of keywords in random order.
Phrase search in GroupDocs.Search
Phrase search allows you to perform search for exact phrase and find a given sequence of words in the text of indexed documents. In text form, the following syntax is used to specify a phrase search query:
“word1 word2 word3 …”
Quotation marks are required, for example:
string query = “\“theory of relativity\””;
Please note that if stop words are used in a search query, the phrase will still be found, however, instead of stop words, the search engine will try to substitute any words.
The following example demonstrates performing the phrase search with a query in text and object form.
constindexFolder='c:/MyIndex/';constdocumentsFolder='c:/MyDocuments/';// Creating an index in the specified folder
constindex=newgroupdocs.search.Index(indexFolder);// Indexing documents from the specified folder
index.add(documentsFolder);// Search for the phrase 'sollicitudin at ligula' in text form
constquery1='"sollicitudin at ligula"';constresult1=index.search(query1);// Search for the phrase 'sollicitudin at ligula' in object form
constword1=groupdocs.search.SearchQuery.createWordQuery('sollicitudin');constword2=groupdocs.search.SearchQuery.createWordQuery('at');constword3=groupdocs.search.SearchQuery.createWordQuery('ligula');constquery2=groupdocs.search.SearchQuery.createPhraseSearchQuery(word1,word2,word3);constresult2=index.search(query2);
Phrase search with wildcards
Phrase search other than words can also use two kinds of wildcard characters:
* byte-number
* byte-number ~~ byte-number
where byte-number is a number from 0 to 255.
The first pattern represents the exact number of unknown words in a phrase, for example *2. The second pattern represents the range of the number of unknown words in a phrase, for example *1~~2.
Phrase search query with wildcards is flexible enough to be used instead of span term query (span query).
The following example demonstrates the use of wildcards in phrase search queries in text and object form.
constindexFolder='c:/MyIndex/';constdocumentsFolder='c:/MyDocuments/';// Creating an index in the specified folder
constindex=newgroupdocs.search.Index(indexFolder);// Indexing documents from the specified folder
index.add(documentsFolder);// Search for the phrase in text form
constquery1='"sollicitudin *0~~3 ligula"';constresult1=index.search(query1);// Search for the phrase in object form
constword1=groupdocs.search.SearchQuery.createWordQuery('sollicitudin');constwildcard2=groupdocs.search.SearchQuery.createWildcardQuery(0,3);constword3=groupdocs.search.SearchQuery.createWordQuery('ligula');constquery2=groupdocs.search.SearchQuery.createPhraseSearchQuery(word1,wildcard2,word3);constresult2=index.search(query2);// The search can find the following phrases:
// "sollicitudin of ligula"
// "sollicitudin ligula"
Phrase search can be combined with other types of searches. The specification of search queries in text form is presented on the Query language specification page. A table of the possibility of nesting search queries in object form is presented on the Nesting search queries in object form page.
The following example demonstrates the use of both wildcards representing words and characters in words.
constindexFolder='c:/MyIndex/';constdocumentsFolder='c:/MyDocuments/';// Creating an index in the specified folder
constindex=newgroupdocs.search.Index(indexFolder);// Indexing documents from the specified folder
index.add(documentsFolder);// Search for the phrase in text form
constquery1='"sollicitudin *0~~3 ?(0~4)la"';constresult1=index.search(query1);// Search for the phrase in object form
constword1=groupdocs.search.SearchQuery.createWordQuery('sollicitudin');constwildcard2=groupdocs.search.SearchQuery.createWildcardQuery(0,3);constpattern=newgroupdocs.search.WordPattern();pattern.appendWildcard(0,4);pattern.appendString('la');constwordPattern3=groupdocs.search.SearchQuery.createWordPatternQuery(pattern);constquery2=groupdocs.search.SearchQuery.createPhraseSearchQuery(word1,wildcard2,wordPattern3);constresult2=index.search(query2);// The search can find the following phrases:
// "sollicitudin of ligula"
// "sollicitudin ligula"
// "sollicitudin, nulla"
More resources
GitHub examples
You may easily run the code from documentation articles and see the features in action in our GitHub examples: