LuceneCoreQuery.dtd: Elements - Entities - Source | Intro - Index
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<!-- - <h3>Background</h3> - This DTD describes the XML syntax used to perform advanced searches using the core Lucene search engine. The motivation behind the XML query syntax is: - <ol> - <li>To open up Lucene functionality to clients other than Java</li> - <li>To offer a form of expressing queries that can easily be - <ul> - <li>Persisted for logging/auditing purposes</li> - <li>Changed by editing text query templates (XSLT) without requiring a recompile/redeploy of applications</li> - <li>Serialized across networks (without requiring Java bytecode for Query logic deployed on clients)</li> - </ul> - </li> - <li>To provide a shorthand way of expressing query logic which echos the logical tree structure of query objects more closely than reading procedural Java query construction code</li> - <li>To bridge the growing gap between Lucene query/filtering functionality and the set of functionality accessible throught the standard Lucene QueryParser syntax</li> - <li>To provide a simply extensible syntax that does not require complex parser skills such as knowledge of JavaCC syntax</li> - </ol> - - - <h3>Syntax overview</h3> - Search syntax consists of two types of elements: - <ul> - <li><i>Queries</i></li> - <li><i>Filters</i></li> - </ul> - - <h4>Queries</h4> - The root of any XML search must be a <i>Query</i> type element used to select content. - Queries typically score matches on documents using a number of different factors in order to provide relevant results first. - One common example of a query tag is the <a href="#UserQuery">UserQuery</a> element which uses the standard - Lucene QueryParser to parse Google-style search syntax provided by end users. - - <h4>Filters</h4> - Unlike Queries, <i>Filters</i> are not used to select or score content - they are simply used to filter <i>Query</i> output (see <a href="#FilteredQuery">FilteredQuery</a> for an example use of query filtering). - Because Filters simply offer a yes/no decision for each document in the index their output can be efficiently cached in memory as a <a href="http://java.sun.com/j2se/1.4.2/docs/api/java/util/BitSet.html">Bitset</a> for - subsequent reuse (see <a href="#CachedFilter">CachedFilter</a> tag). - - <h4>Nesting elements</h4> - Many of the the elements can nest other elements to produce queries/filters of an arbitrary depth and complexity. - The <a href="#BooleanQuery">BooleanQuery</a> element is one such example which provides a means for combining other queries (including other BooleanQueries) using Boolean - logic to determine mandatory or optional elements. - - - <h3>Advanced topics</h3> - <h4>Advanced positional testing - span queries</h4> - The <i>SpanQuery</i> class of queries allow for complex positional tests which not only look for certain combinations of words but in particular - positions in relation to each other and the documents containing them. - - - CoreParser.java is the Java class that encapsulates this parser behaviour. - - - @title Core Lucene ---> - -<!-- @hidden Define core types of XML elements --> -<!ENTITY % coreSpanQueries "SpanOr|SpanNear|SpanOrTerms|SpanFirst|SpanNot|SpanTerm|BoostingTermQuery" > -<!ENTITY % coreQueries "BooleanQuery|UserQuery|FilteredQuery|TermQuery|TermsQuery|MatchAllDocsQuery|ConstantScoreQuery|BoostingTermQuery|NumericRangeQuery" > -<!ENTITY % coreFilters "RangeFilter|NumericRangeFilter|CachedFilter" > - -<!-- @hidden Allow for extensions --> -<!ENTITY % extendedSpanQueries1 " " > -<!ENTITY % extendedQueries1 " " > -<!ENTITY % extendedFilters1 " " > - -<!ENTITY % spanQueries "%coreSpanQueries;%extendedSpanQueries1;" > -<!ENTITY % queries "%coreQueries;|%spanQueries;%extendedQueries1;" > - - -<!ENTITY % filters "%coreFilters;%extendedFilters1;" > - -<!-- - BooleanQuerys implement Boolean logic which controls how multiple Clauses should be interpreted. - Some clauses may represent optional Query criteria while others represent mandatory criteria. - @example - <em>Find articles about banks, preferably talking about mergers but nothing to do with "sumitomo"</em> - % - <BooleanQuery fieldName="contents"> - <Clause occurs="should"> - <TermQuery>merger</TermQuery> - </Clause> - <Clause occurs="mustnot"> - <TermQuery>sumitomo</TermQuery> - </Clause> - <Clause occurs="must"> - <TermQuery>bank</TermQuery> - </Clause> - </BooleanQuery> - - % ---> -<!ELEMENT BooleanQuery (Clause)+> -<!-- Optional boost for matches on this query. Values > 1 --> -<!ATTLIST BooleanQuery boost CDATA "1.0"> -<!-- fieldName can optionally be defined here as a default attribute used by all child elements --> -<!ATTLIST BooleanQuery fieldName CDATA #IMPLIED> -<!-- The "Coordination factor" rewards documents that contain more of the optional clauses in this list. This flag can be used to turn off this factor. --> -<!ATTLIST BooleanQuery disableCoord (true | false) "false"> -<!-- The minimum number of optional clauses that should be present in any one document before it is considered to be a match. --> -<!ATTLIST BooleanQuery minimumNumberShouldMatch CDATA "0"> - -<!-- NOTE: "Clause" tag has 2 modes of use - inside <BooleanQuery> in which case only "query" types can be - child elements - while in a <BooleanFilter> clause only "filter" types can be contained. - @hidden TODO: Change BooleanFilterBuilder and BooleanQueryBuilder to auto-wrap choice of query or filters. This type of - code already exists in CachedFilter so could be reused. ---> -<!ELEMENT Clause (%queries;|%filters;)> -<!-- Controls if the clause is optional (should), mandatory (must) or unacceptable (mustNot) --> -<!ATTLIST Clause occurs (should | must | mustnot) "should"> - - -<!-- Caches any nested query or filter in an LRU (Least recently used) Cache. Cached queries, like filters, are turned into - Bitsets at a cost of 1 bit per document in the index. The memory cost of a cached query/filter is therefore numberOfDocsinIndex/8 bytes. - Queries that are cached as filters obviously retain none of the scoring information associated with results - they retain just - a Boolean yes/no record of which documents matched. - @example - <em>Search for documents about banks from the last 10 years - caching the commonly-used "last 10 year" filter as a BitSet in - RAM to eliminate the cost of building this filter from disk for every query</em> - % - <FilteredQuery> - <Query> - <UserQuery>bank</UserQuery> - </Query> - <Filter> - <CachedFilter> - <RangeFilter fieldName="date" lowerTerm="19970101" upperTerm="20070101"/> - </CachedFilter> - </Filter> - </FilteredQuery> - % - - --> -<!ELEMENT CachedFilter (%queries;|%filters;)> - - - -<!-- -Passes content directly through to the standard LuceneQuery parser see "Lucene Query Syntax" - @example - <em>Search for documents about John Smith or John Doe using standard LuceneQuerySyntax</em> - % - <UserQuery>"John Smith" OR "John Doe"</UserQuery> - % - ---> -<!ELEMENT UserQuery (#PCDATA)> -<!-- Optional boost for matches on this query. Values > 1 --> -<!ATTLIST UserQuery boost CDATA "1.0"> -<!-- fieldName can optionally be defined here to change the default field used in the QueryParser --> -<!ATTLIST UserQuery fieldName CDATA #IMPLIED> - -<!-- A query which is used to match all documents. This has a couple of uses: - <ol> - <li> as a Clause in a BooleanQuery who's only other clause - is a "mustNot" match (Lucene requires at least one positive clause) and..</li> - <li> in a FilteredQuery where a Filter tag is effectively being - used to select content rather than it's usual role of filtering the results of a query.</li> - </ol> - - @example - <em>Effectively use a Filter as a query </em> - % - <FilteredQuery> - <Query> - <MatchAllDocsQuery/> - </Query> - <Filter> - <RangeFilter fieldName="date" lowerTerm="19870409" upperTerm="19870412"/> - </Filter> - </FilteredQuery> - % - ---> -<!ELEMENT MatchAllDocsQuery EMPTY> - -<!-- a single term query - no analysis is done of the child text - @example - <em>Match on a primary key</em> - % - <TermQuery fieldName="primaryKey">13424</TermQuery> - % ---> -<!ELEMENT TermQuery (#PCDATA)> -<!-- Optional boost for matches on this query. Values > 1 --> -<!ATTLIST TermQuery boost CDATA "1.0"> -<!-- fieldName must be defined here or is taken from the most immediate parent XML element that defines a "fieldName" attribute --> -<!ATTLIST TermQuery fieldName CDATA #IMPLIED> - - -<!-- - A boosted term query - no analysis is done of the child text. Also a span member. - - (Text below is copied from the javadocs of BoostingTermQuery) - - The BoostingTermQuery is very similar to the {@link org.apache.lucene.search.spans.SpanTermQuery} except - that it factors in the value of the payload located at each of the positions where the - {@link org.apache.lucene.index.Term} occurs. - - In order to take advantage of this, you must override {@link org.apache.lucene.search.Similarity#scorePayload(String, byte[],int,int)} - which returns 1 by default. - - Payload scores are averaged across term occurrences in the document. - - @see org.apache.lucene.search.Similarity#scorePayload(String, byte[], int, int) ---> -<!ELEMENT BoostingTermQuery (#PCDATA)> -<!-- Optional boost for matches on this query. Values > 1 --> -<!ATTLIST TermQuery boost CDATA "1.0"> -<!-- fieldName must be defined here or is taken from the most immediate parent XML element that defines a "fieldName" attribute --> -<!ATTLIST TermQuery fieldName CDATA #IMPLIED> - - - -<!-- - The equivalent of a BooleanQuery with multiple optional TermQuery clauses. - Child text is analyzed using a field-specific choice of Analyzer to produce a set of terms that are ORed together in Boolean logic. - Unlike UserQuery element, this does not parse any special characters to control fuzzy/phrase/boolean logic and as such is incapable - of producing a Query parse error given any user input - @example - <em>Match on text from a database description (which may contain characters that - are illegal characters in the standard Lucene Query syntax used in the UserQuery tag</em> - % - <TermsQuery fieldName="description">Smith & Sons (Ltd) : incorporated 1982</TermsQuery> - % ---> -<!ELEMENT TermsQuery (#PCDATA)> -<!-- Optional boost for matches on this query. Values > 1 --> -<!ATTLIST TermsQuery boost CDATA "1.0"> -<!-- fieldName must be defined here or is taken from the most immediate parent XML element that defines a "fieldName" attribute --> -<!ATTLIST TermsQuery fieldName CDATA #IMPLIED> -<!-- The "Coordination factor" rewards documents that contain more of the terms in this list. This flag can be used to turn off this factor. --> -<!ATTLIST TermsQuery disableCoord (true | false) "false"> -<!-- The minimum number of terms that should be present in any one document before it is considered to be a match. --> -<!ATTLIST TermsQuery minimumNumberShouldMatch CDATA "0"> - - -<!-- - Runs a Query and filters results to only those query matches that also match the Filter element. - @example - <em>Find all documents about Lucene that have a status of "published"</em> - % - <FilteredQuery> - <Query> - <UserQuery>Lucene</UserQuery> - </Query> - <Filter> - <TermsFilter fieldName="status">published</TermsFilter> - </Filter> - </FilteredQuery> - % ---> -<!ELEMENT FilteredQuery (Query,Filter)> -<!-- Optional boost for matches on this query. Values > 1 --> -<!ATTLIST FilteredQuery boost CDATA "1.0"> -<!-- Used to identify a nested Query element inside another container element. NOT a top-level query tag --> -<!ELEMENT Query (%queries;)> -<!-- The choice of Filter that MUST also be matched --> -<!ELEMENT Filter (%filters;)> - -<!-- - Filter used to limit query results to documents matching a range of field values - @example - <em>Search for documents about banks from the last 10 years</em> - % - <FilteredQuery> - <Query> - <UserQuery>bank</UserQuery> - </Query> - <Filter> - <RangeFilter fieldName="date" lowerTerm="19970101" upperTerm="20070101"/> - </Filter> - </FilteredQuery> - % - --> -<!ELEMENT RangeFilter EMPTY> -<!-- fieldName must be defined here or is taken from the most immediate parent XML element that defines a "fieldName" attribute --> -<!ATTLIST RangeFilter fieldName CDATA #IMPLIED> -<!-- The lower-most term value for this field (must be <= upperTerm) --> -<!ATTLIST RangeFilter lowerTerm CDATA #REQUIRED> -<!-- The upper-most term value for this field (must be >= lowerTerm) --> -<!ATTLIST RangeFilter upperTerm CDATA #REQUIRED> -<!-- Controls if the lowerTerm in the range is part of the allowed set of values --> -<!ATTLIST RangeFilter includeLower (true | false) "true"> -<!-- Controls if the upperTerm in the range is part of the allowed set of values --> -<!ATTLIST RangeFilter includeUpper (true | false) "true"> - -<!-- - A Query that matches numeric values within a specified range. - @example - <em>Search for documents about people who are aged 20-25</em> - % - <NumericRangeQuery fieldName="age" lowerTerm="20" upperTerm="25" /> - % - --> -<!ELEMENT NumericRangeQuery EMPTY> -<!-- fieldName must be defined here or is taken from the most immediate parent XML element that defines a "fieldName" attribute --> -<!ATTLIST NumericRangeQuery fieldName CDATA #IMPLIED> -<!-- The lower-most term value for this field (must be <= upperTerm and a valid native java numeric type) --> -<!ATTLIST NumericRangeQuery lowerTerm CDATA #REQUIRED> -<!-- The upper-most term value for this field (must be >= lowerTerm and a valid native java numeric type) --> -<!ATTLIST NumericRangeQuery upperTerm CDATA #REQUIRED> -<!-- The numeric type of this field --> -<!ATTLIST NumericRangeQuery type (int | long | float | double) "int"> -<!-- Controls if the lowerTerm in the range is part of the allowed set of values --> -<!ATTLIST NumericRangeQuery includeLower (true | false) "true"> -<!-- Controls if the upperTerm in the range is part of the allowed set of values --> -<!ATTLIST NumericRangeQuery includeUpper (true | false) "true"> -<!-- Lower step values mean more precisions and so more terms in index (and index gets larger). This value must be an integer --> -<!ATTLIST NumericRangeQuery precisionStep CDATA "4"> - -<!-- - A Filter that only accepts numeric values within a specified range - @example - <em>Search for documents about people who are aged 20-25</em> - % - <FilteredQuery> - <Query> - <UserQuery>person</UserQuery> - </Query> - <Filter> - <NumericRangeFilter fieldName="age" lowerTerm="20" upperTerm="25"/> - </Filter> - </FilteredQuery> - % - --> -<!ELEMENT NumericRangeFilter EMPTY> -<!-- fieldName must be defined here or is taken from the most immediate parent XML element that defines a "fieldName" attribute --> -<!ATTLIST NumericRangeFilter fieldName CDATA #IMPLIED> -<!-- The lower-most term value for this field (must be <= upperTerm and a valid native java numeric type) --> -<!ATTLIST NumericRangeFilter lowerTerm CDATA #REQUIRED> -<!-- The upper-most term value for this field (must be >= lowerTerm and a valid native java numeric type) --> -<!ATTLIST NumericRangeFilter upperTerm CDATA #REQUIRED> -<!-- The numeric type of this field --> -<!ATTLIST NumericRangeFilter type (int | long | float | double) "int"> -<!-- Controls if the lowerTerm in the range is part of the allowed set of values --> -<!ATTLIST NumericRangeFilter includeLower (true | false) "true"> -<!-- Controls if the upperTerm in the range is part of the allowed set of values --> -<!ATTLIST NumericRangeFilter includeUpper (true | false) "true"> -<!-- Lower step values mean more precisions and so more terms in index (and index gets larger). This value must be an integer --> -<!ATTLIST NumericRangeFilter precisionStep CDATA "4"> - -<!-- A single term used in a SpanQuery. These clauses are the building blocks for more complex "span" queries which test word proximity - @example <em>Find documents using terms close to each other about mining and accidents</em> - % - <SpanNear slop="8" inOrder="false" fieldName="text"> - <SpanOr> - <SpanTerm>killed</SpanTerm> - <SpanTerm>died</SpanTerm> - <SpanTerm>dead</SpanTerm> - </SpanOr> - <SpanOr> - <SpanTerm>miner</SpanTerm> - <SpanTerm>mining</SpanTerm> - <SpanTerm>miners</SpanTerm> - </SpanOr> - </SpanNear> - % - --> -<!ELEMENT SpanTerm (#PCDATA)> -<!-- fieldName must be defined here or is taken from the most immediate parent XML element that defines a "fieldName" attribute --> -<!ATTLIST SpanTerm fieldName CDATA #REQUIRED> - -<!-- A field-specific analyzer is used here to parse the child text provided in this tag. The SpanTerms produced are ORed in terms of Boolean logic - @example <em>Use SpanOrTerms as a more convenient/succinct way of expressing multiple choices of SpanTerms. This example looks for reports - using words describing a fatality near to references to miners</em> - % - <SpanNear slop="8" inOrder="false" fieldName="text"> - <SpanOrTerms>killed died death dead deaths</SpanOrTerms> - <SpanOrTerms>miner mining miners</SpanOrTerms> - </SpanNear> - % - --> -<!ELEMENT SpanOrTerms (#PCDATA)> -<!-- fieldName must be defined here or is taken from the most immediate parent XML element that defines a "fieldName" attribute --> -<!ATTLIST SpanOrTerms fieldName CDATA #REQUIRED> - -<!-- Takes any number of child queries from the Span family - @example <em>Find documents using terms close to each other about mining and accidents</em> - % - <SpanNear slop="8" inOrder="false" fieldName="text"> - <SpanOr> - <SpanTerm>killed</SpanTerm> - <SpanTerm>died</SpanTerm> - <SpanTerm>dead</SpanTerm> - </SpanOr> - <SpanOr> - <SpanTerm>miner</SpanTerm> - <SpanTerm>mining</SpanTerm> - <SpanTerm>miners</SpanTerm> - </SpanOr> - </SpanNear> - % - - --> -<!ELEMENT SpanOr (%spanQueries;)* > - -<!-- Takes any number of child queries from the Span family and tests for proximity - @hidden TODO SpanNear missing "boost attr (could add to SpanBuilderBase) - --> -<!ELEMENT SpanNear (%spanQueries;)* > -<!-- defines the maximum distance between Span elements where distance is expressed as word number, not byte offset - @example <em>Find documents using terms within 8 words of each other talking about mining and accidents</em> - % - <SpanNear slop="8" inOrder="false" fieldName="text"> - <SpanOr> - <SpanTerm>killed</SpanTerm> - <SpanTerm>died</SpanTerm> - <SpanTerm>dead</SpanTerm> - </SpanOr> - <SpanOr> - <SpanTerm>miner</SpanTerm> - <SpanTerm>mining</SpanTerm> - <SpanTerm>miners</SpanTerm> - </SpanOr> - </SpanNear> - % - --> -<!ATTLIST SpanNear slop CDATA #REQUIRED> -<!-- Controls if matching terms have to appear in the order listed or can be reversed --> -<!ATTLIST SpanNear inOrder (true | false) "true"> - -<!-- Looks for a SpanQuery match occuring near the beginning of a document - - @example - <em>Find letters where the first 50 words talk about a resignation:</em> - % - <SpanFirst end="50"> - <SpanOrTerms fieldName="text">resigning resign leave</SpanOrTerms> - </SpanFirst> - % - - --> -<!ELEMENT SpanFirst (%spanQueries;) > -<!-- Controls the end of the region considered in a document's field (expressed in word number, not byte offset) --> -<!ATTLIST SpanFirst end CDATA #REQUIRED> -<!-- Optional boost for matches on this query. Values > 1 --> -<!ATTLIST SpanFirst boost CDATA "1.0"> - -<!-- Finds documents matching a SpanQuery but not if matching another SpanQuery - @example <em>Find documents talking about social services but not containing the word "public"</em> - % - <SpanNot fieldName="text"> - <Include> - <SpanNear slop="2" inOrder="true"> - <SpanTerm>social</SpanTerm> - <SpanTerm>services</SpanTerm> - </SpanNear> - </Include> - <Exclude> - <SpanTerm>public</SpanTerm> - </Exclude> - </SpanNot> - % - - --> -<!ELEMENT SpanNot (Include,Exclude) > -<!-- The SpanQuery to find --> -<!ELEMENT Include (%spanQueries;) > -<!-- The SpanQuery to be avoided --> -<!ELEMENT Exclude (%spanQueries;) > - - -<!-- a utility tag to wrap any filter as a query - @example <em> Find all documents from the last 10 years </em> - % - <ConstantScoreQuery> - <RangeFilter fieldName="date" lowerTerm="19970101" upperTerm="20070101"/> - </ConstantScoreQuery> - % - --> -<!ELEMENT ConstantScoreQuery (%filters;)* > -<!-- Optional boost for matches on this query. Values > 1 --> -<!ATTLIST ConstantScoreQuery boost CDATA "1.0"> - - - --