Class PhraseQuery

A Query that matches documents containing a particular sequence of terms. A PhraseQuery is built by QueryParser for input like "new york".

This query may be combined with other terms or queries with a BooleanQuery.

Collection initializer note: To create and populate a PhraseQuery in a single statement, you can use the following example as a guide:

var phraseQuery = new PhraseQuery() {
    new Term("field", "microsoft"), 
    new Term("field", "office")
};

Note that as long as you specify all of the parameters, you can use either Add(Term) or Add(Term, Int32) as the method to use to initialize. If there are multiple parameters, each parameter set must be surrounded by curly braces.

Inheritance

System.Object

Query

PhraseQuery

NGramPhraseQuery

Implements

System.Collections.Generic.IEnumerable<Term>

System.Collections.IEnumerable

Inherited Members

Query.Boost

Query.ToString()

Query.Clone()

System.Object.Equals(System.Object, System.Object)

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

Namespace: Lucene.Net.Search

Assembly: Lucene.Net.dll

Syntax

public class PhraseQuery : Query, IEnumerable<Term>, IEnumerable

Constructors

PhraseQuery()

Constructs an empty phrase query.

Declaration

public PhraseQuery()

Properties

Slop

Sets the number of other words permitted between words in query phrase. If zero, then this is an exact phrase search. For larger values this works like a WITHIN or NEAR operator.

The slop is in fact an edit-distance, where the units correspond to moves of terms in the query phrase out of position. For example, to switch the order of two words requires two moves (the first move places the words atop one another), so to permit re-orderings of phrases, the slop must be at least two.

More exact matches are scored higher than sloppier matches, thus search results are sorted by exactness.

The slop is zero by default, requiring exact matches.

Declaration

public virtual int Slop { get; set; }

Property Value

Type	Description
System.Int32

Methods

Add(Term)

Adds a term to the end of the query phrase. The relative position of the term is the one immediately after the last term added.

Declaration

public virtual void Add(Term term)

Parameters

Type	Name	Description
Term	term

Add(Term, Int32)

Adds a term to the end of the query phrase. The relative position of the term within the phrase is specified explicitly. this allows e.g. phrases with more than one term at the same position or phrases with gaps (e.g. in connection with stopwords).

Declaration

public virtual void Add(Term term, int position)

Parameters

Type	Name	Description
Term	term
System.Int32	position

CreateWeight(IndexSearcher)

Declaration

public override Weight CreateWeight(IndexSearcher searcher)

Parameters

Type	Name	Description
IndexSearcher	searcher

Returns

Type	Description
Weight

Overrides

Query.CreateWeight(IndexSearcher)

Equals(Object)

Returns true if o is equal to this.

Declaration

public override bool Equals(object o)

Parameters

Type	Name	Description
System.Object	o

Returns

Type	Description
System.Boolean

Overrides

Query.Equals(Object)

ExtractTerms(ISet<Term>)

Declaration

public override void ExtractTerms(ISet<Term> queryTerms)

Parameters

Type	Name	Description
System.Collections.Generic.ISet<Term>	queryTerms

Overrides

Query.ExtractTerms(ISet<Term>)

See Also

ExtractTerms(System.Collections.Generic.ISet<Term>)

GetEnumerator()

Returns an enumerator that iterates through the Lucene.Net.Search.PhraseQuery.terms collection.

Declaration

public IEnumerator<Term> GetEnumerator()

Returns

Type	Description
System.Collections.Generic.IEnumerator<Term>	An enumerator that can be used to iterate through the Lucene.Net.Search.PhraseQuery.terms collection.

GetHashCode()

Returns a hash code value for this object.

Declaration

public override int GetHashCode()

Returns

Type	Description
System.Int32

Overrides

Query.GetHashCode()

GetPositions()

Returns the relative positions of terms in this phrase.

Declaration

public virtual int[] GetPositions()

Returns

Type	Description
System.Int32[]

GetTerms()

Returns the set of terms in this phrase.

Declaration

public virtual Term[] GetTerms()

Returns

Type	Description
Term[]

Rewrite(IndexReader)

Declaration

public override Query Rewrite(IndexReader reader)

Parameters

Type	Name	Description
IndexReader	reader

Returns

Type	Description
Query

Overrides

Query.Rewrite(IndexReader)

ToString(String)

Prints a user-readable version of this query.

Declaration

public override string ToString(string f)

Parameters

Type	Name	Description
System.String	f

Returns

Type	Description
System.String

Overrides

Query.ToString(String)

Explicit Interface Implementations

IEnumerable.GetEnumerator()

Returns an enumerator that iterates through the Lucene.Net.Search.PhraseQuery.terms collection.

Declaration

IEnumerator IEnumerable.GetEnumerator()

Returns

Type	Description
System.Collections.IEnumerator	An enumerator that can be used to iterate through the Lucene.Net.Search.PhraseQuery.terms collection.

Implements

System.Collections.Generic.IEnumerable<T>

System.Collections.IEnumerable

Extension Methods

EnumerableExtensions.InPairs<T, TOut>(IEnumerable<T>, Func<T, T, TOut>)

Number.IsNumber(Object)