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
object
QueryParserHelper<Query>
StandardQueryParser
PrecedenceQueryParser
Inherited Members
Namespace: Lucene.Net.QueryParsers.Flexible.Standard
Assembly: Lucene.Net.QueryParser.dll
Syntax
public class StandardQueryParser : QueryParserHelper<Query>, ICommonQueryParserConfiguration

Constructors

StandardQueryParser()

Constructs a StandardQueryParser object.

Declaration
public StandardQueryParser()
See Also

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
Analyzer analyzer

the analyzer to be used by this query parser helper
See Also

Properties

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
bool
See Also

Analyzer

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.

Declaration
public virtual Analyzer Analyzer { get; set; }
Property Value
Type Description
Analyzer
See Also

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
DateResolution?
See Also

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
IDictionary<string, DateResolution>
See Also

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
See Also

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
bool
See Also

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
IDictionary<string, float>
See Also

FuzzyMinSim

Gets or Sets the minimum similarity for fuzzy queries. Default is defined on Lucene.Net.Search.FuzzyQuery.DefaultMinSimilarity.

Declaration
public virtual float FuzzyMinSim { get; set; }
Property Value
Type Description
float
See Also

FuzzyPrefixLength

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

Declaration
public virtual int FuzzyPrefixLength { get; set; }
Property Value
Type Description
int
See Also

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
CultureInfo
See Also

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
bool
See Also

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
MultiTermQuery.RewriteMethod
See Also

NumericConfigMap

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.

Declaration
public virtual IDictionary<string, NumericConfig> NumericConfigMap { get; set; }
Property Value
Type Description
IDictionary<string, NumericConfig>
See Also

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
int
See Also

TimeZone

Gets or Sets the time zone.

Declaration
public virtual TimeZoneInfo TimeZone { get; set; }
Property Value
Type Description
TimeZoneInfo
See Also

Methods

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
string[]

the fields used to expand the query
See Also

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
string query

the query string
string defaultField

the default field used by the text parser
Returns
Type Description
Query

the object built from the query
Overrides
Exceptions
Type Condition
QueryNodeException

if something wrong happens along the three phases
See Also

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
DateResolution dateResolution

the default Lucene.Net.Documents.DateResolution
See Also

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
IDictionary<string, DateResolution> dateRes

a collection that maps a field to its Lucene.Net.Documents.DateResolution
See Also

SetDefaultPhraseSlop(int)

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
int defaultPhraseSlop
See Also

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
string[] fields

the fields used to expand the query
See Also

ToString()

Returns a string that represents the current object.

Declaration
public override string ToString()
Returns
Type Description
string

A string that represents the current object.
Overrides
See Also

Implements

See Also