Class StandardQueryParser

This class is a helper that enables users to easily use the Lucene query parser.

To construct a Query object from a query string, use the Parse(String, String) method:

StandardQueryParser queryParserHelper = new StandardQueryParser();
Query query = queryParserHelper.Parse("a AND b", "defaultField");

To change any configuration before parsing the query string do, for example:

queryParserHelper.Analyzer = new WhitespaceAnalyzer();
queryParserHelper.AllowLeadingWildcard = true;
// Or alternativley use the query config handler returned by StandardQueryParser which is a
// StandardQueryConfigHandler:
queryParserHelper.QueryConfigHandler.Set(ConfigurationKeys.ALLOW_LEADING_WILDCARD, true);

The syntax for query strings is as follows (copied from the old QueryParser javadoc):

A Query is a series of clauses. A clause may be prefixed by:

a plus (+) or a minus (-) sign, indicating that the clause is required or prohibited respectively; or
a term followed by a colon, indicating the field to be searched. This enables one to construct queries which search multiple fields.

A clause may be either:

a term, indicating all the documents that contain this term; or
a nested query, enclosed in parentheses. Note that this may be used with a +/- prefix to require any of a set of terms.

Thus, in BNF, the query grammar is:

    Query  ::= ( Clause )*
    Clause ::= ["+", "-"] [<TERM> ":"] ( <TERM> | "(" Query ")" )

Examples of appropriately formatted queries can be found in the query syntax documentation.

The text parser used by this helper is a StandardSyntaxParser.

The query node processor used by this helper is a StandardQueryNodeProcessorPipeline.

The builder used by this helper is a StandardQueryTreeBuilder.

Inheritance

System.Object

QueryParserHelper<Lucene.Net.Search.Query>

StandardQueryParser

PrecedenceQueryParser

Implements

ICommonQueryParserConfiguration

Inherited Members

QueryParserHelper<Query>.QueryNodeProcessor

QueryParserHelper<Query>.SetQueryNodeProcessor(IQueryNodeProcessor)

QueryParserHelper<Query>.SetSyntaxParser(ISyntaxParser)

QueryParserHelper<Query>.SetQueryBuilder(IQueryBuilder<Query>)

QueryParserHelper<Query>.QueryConfigHandler

QueryParserHelper<Query>.QueryBuilder

QueryParserHelper<Query>.SyntaxParser

QueryParserHelper<Query>.SetQueryConfigHandler(QueryConfigHandler)

System.Object.Equals(System.Object)

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

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

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

Namespace: Lucene.Net.QueryParsers.Flexible.Standard

Assembly: Lucene.Net.QueryParser.dll

Syntax

public class StandardQueryParser : QueryParserHelper<Query>, ICommonQueryParserConfiguration

Constructors

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StandardQueryParser()

Constructs a StandardQueryParser object.

Declaration

public StandardQueryParser()

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StandardQueryParser(Analyzer)

Constructs a StandardQueryParser object and sets an Lucene.Net.Analysis.Analyzer to it. The same as:

StandardQueryParser qp = new StandardQueryParser();
qp.QueryConfigHandler.Analyzer = analyzer;

Declaration

public StandardQueryParser(Analyzer analyzer)

Parameters

Type	Name	Description
Lucene.Net.Analysis.Analyzer	analyzer	the analyzer to be used by this query parser helper

Properties

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AllowLeadingWildcard

Set to true to allow leading wildcard characters.

When set, * or ? are allowed as the first character of a Lucene.Net.Search.PrefixQuery and Lucene.Net.Search.WildcardQuery. Note that this can produce very slow queries on big indexes.

Default: false.

Declaration

public virtual bool AllowLeadingWildcard { get; set; }

Property Value

Type	Description
System.Boolean

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Analyzer

Declaration

public virtual Analyzer Analyzer { get; set; }

Property Value

Type	Description
Lucene.Net.Analysis.Analyzer

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DateResolution

Gets the default Lucene.Net.Documents.DateResolution used for certain field when no Lucene.Net.Documents.DateResolution is defined for this field.

Declaration

public virtual DateResolution? DateResolution { get; }

Property Value

Type	Description
System.Nullable<Lucene.Net.Documents.DateResolution>

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DateResolutionMap

Gets or Sets the field to Lucene.Net.Documents.DateResolution map used to normalize each date field.

Declaration

public virtual IDictionary<string, DateResolution> DateResolutionMap { get; set; }

Property Value

Type	Description
System.Collections.Generic.IDictionary<System.String, Lucene.Net.Documents.DateResolution>

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DefaultOperator

Gets or Sets the boolean operator of the QueryParser. In default mode ( OR) terms without any modifiers are considered optional: for example capital of Hungary is equal to capital OR of OR Hungary.

In AND mode terms are considered to be in conjunction: the above mentioned query is parsed as capital AND of AND Hungary

Declaration

public virtual StandardQueryConfigHandler.Operator DefaultOperator { get; set; }

Property Value

Type	Description
StandardQueryConfigHandler.Operator

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EnablePositionIncrements

Set to true to enable position increments in result query.

When set, result phrase and multi-phrase queries will be aware of position increments. Useful when e.g. a Lucene.Net.Analysis.Core.StopFilter increases the position increment of the token that follows an omitted token.

Default: false.

Declaration

public virtual bool EnablePositionIncrements { get; set; }

Property Value

Type	Description
System.Boolean

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FieldsBoost

Gets or Sets the field to boost map used to set boost for each field.

Declaration

public virtual IDictionary<string, float> FieldsBoost { get; set; }

Property Value

Type	Description
System.Collections.Generic.IDictionary<System.String, System.Single>

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FuzzyMinSim

Gets or Sets the minimum similarity for fuzzy queries. Default is defined on DefaultMinSimilarity.

Declaration

public virtual float FuzzyMinSim { get; set; }

Property Value

Type	Description
System.Single

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FuzzyPrefixLength

Gets or Sets the prefix length for fuzzy queries. Default is 0.

Declaration

public virtual int FuzzyPrefixLength { get; set; }

Property Value

Type	Description
System.Int32

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Locale

Gets or Sets current locale, allowing access by subclasses. Used by date range parsing

Declaration

public virtual CultureInfo Locale { get; set; }

Property Value

Type	Description
System.Globalization.CultureInfo

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LowercaseExpandedTerms

Set to true to allow leading wildcard characters.

When set, * or ? are allowed as the first character of a Lucene.Net.Search.PrefixQuery and Lucene.Net.Search.WildcardQuery. Note that this can produce very slow queries on big indexes.

Default: false.

Declaration

public virtual bool LowercaseExpandedTerms { get; set; }

Property Value

Type	Description
System.Boolean

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MultiTermRewriteMethod

By default, it uses Lucene.Net.Search.MultiTermQuery.CONSTANT_SCORE_AUTO_REWRITE_DEFAULT when creating a prefix, wildcard and range queries. This implementation is generally preferable because it a) Runs faster b) Does not have the scarcity of terms unduly influence score c) avoids any Exception due to too many listeners. However, if your application really needs to use the old-fashioned boolean queries expansion rewriting and the above points are not relevant then use this change the rewrite method.

Declaration

public virtual MultiTermQuery.RewriteMethod MultiTermRewriteMethod { get; set; }

Property Value

Type	Description
Lucene.Net.Search.MultiTermQuery.RewriteMethod

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NumericConfigMap

Declaration

public virtual IDictionary<string, NumericConfig> NumericConfigMap { get; set; }

Property Value

Type	Description
System.Collections.Generic.IDictionary<System.String, NumericConfig>

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PhraseSlop

Gets or Sets the default slop for phrases. If zero, then exact phrase matches are required. Default value is zero. NOTE: Setter is deprecated.

Declaration

public virtual int PhraseSlop { get; set; }

Property Value

Type	Description
System.Int32

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TimeZone

Declaration

public virtual TimeZoneInfo TimeZone { get; set; }

Property Value

Type	Description
System.TimeZoneInfo

Methods

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GetMultiFields()

Returns the fields used to expand the query when the field for a certain query is null

Declaration

public virtual string[] GetMultiFields()

Returns

Type	Description
System.String[]	the fields used to expand the query

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Parse(String, String)

Overrides Parse(String, String) so it casts the return object to Lucene.Net.Search.Query. For more reference about this method, check Parse(String, String).

Declaration

public override Query Parse(string query, string defaultField)

Parameters

Type	Name	Description
System.String	query	the query string
System.String	defaultField	the default field used by the text parser

Returns

Type	Description
Lucene.Net.Search.Query	the object built from the query

Overrides

Lucene.Net.QueryParsers.Flexible.Core.QueryParserHelper<Lucene.Net.Search.Query>.Parse(System.String, System.String)

Exceptions

Type	Condition
QueryNodeException	if something wrong happens along the three phases

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SetDateResolution(DateResolution)

Sets the default Lucene.Net.Documents.DateResolution used for certain field when no Lucene.Net.Documents.DateResolution is defined for this field.

Declaration

public virtual void SetDateResolution(DateResolution dateResolution)

Parameters

Type	Name	Description
Lucene.Net.Documents.DateResolution	dateResolution	the default Lucene.Net.Documents.DateResolution

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SetDateResolution(IDictionary<String, DateResolution>)

Sets the Lucene.Net.Documents.DateResolution used for each field

Declaration

[Obsolete("Use DateResolutionMap property instead.")]
public virtual void SetDateResolution(IDictionary<string, DateResolution> dateRes)

Parameters

Type	Name	Description
System.Collections.Generic.IDictionary<System.String, Lucene.Net.Documents.DateResolution>	dateRes	a collection that maps a field to its Lucene.Net.Documents.DateResolution

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SetDefaultPhraseSlop(Int32)

Sets the default slop for phrases. If zero, then exact phrase matches are required. Default value is zero.

Declaration

[Obsolete("Use PhraseSlop property setter instead.")]
public virtual void SetDefaultPhraseSlop(int defaultPhraseSlop)

Parameters

Type	Name	Description
System.Int32	defaultPhraseSlop

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SetMultiFields(String[])

Set the fields a query should be expanded to when the field is null

Declaration

public virtual void SetMultiFields(string[] fields)

Parameters

Type	Name	Description
System.String[]	fields	the fields used to expand the query

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ToString()

Declaration

public override string ToString()

Returns

Type	Description
System.String

Overrides

System.Object.ToString()

Implements

ICommonQueryParserConfiguration