Class ToParentBlockJoinQuery

This query requires that you index children and parent docs as a single block, using the AddDocuments(IEnumerable<IEnumerable<IIndexableField>>, Analyzer) or UpdateDocuments(Term, IEnumerable<IEnumerable<IIndexableField>>, Analyzer) API. In each block, the child documents must appear first, ending with the parent document. At search time you provide a Lucene.Net.Search.Filter identifying the parents, however this Lucene.Net.Search.Filter must provide an Lucene.Net.Util.FixedBitSet per sub-reader.

Once the block index is built, use this query to wrap any sub-query matching only child docs and join matches in that child document space up to the parent document space. You can then use this Lucene.Net.Search.Query as a clause with other queries in the parent document space.

See ToChildBlockJoinQuery if you need to join in the reverse order.

The child documents must be orthogonal to the parent documents: the wrapped child query must never return a parent document.

If you'd like to retrieve Lucene.Net.Search.Grouping.ITopGroups<TGroupValue> for the resulting query, use the ToParentBlockJoinCollector. Note that this is not necessary, ie, if you simply want to collect the parent documents and don't need to see which child documents matched under that parent, then you can use any collector.

NOTE: If the overall query contains parent-only matches, for example you OR a parent-only query with a joined child-only query, then the resulting collected documents will be correct, however the Lucene.Net.Search.Grouping.ITopGroups<TGroupValue> you get from ToParentBlockJoinCollector will not contain every child for parents that had matched.

See http://lucene.apache.org/core/4_8_0/join/ for an overview.

Note

This API is experimental and might change in incompatible ways in the next release.

Inheritance
System.Object
Lucene.Net.Search.Query
ToParentBlockJoinQuery
Inherited Members
Lucene.Net.Search.Query.Boost
Lucene.Net.Search.Query.ToString()
Lucene.Net.Search.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.Join
Assembly: Lucene.Net.Join.dll
Syntax
public class ToParentBlockJoinQuery : Query

Constructors

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ToParentBlockJoinQuery(Query, Filter, ScoreMode)

Create a ToParentBlockJoinQuery.

Declaration
public ToParentBlockJoinQuery(Query childQuery, Filter parentsFilter, ScoreMode scoreMode)
Parameters
Type Name Description
Lucene.Net.Search.Query childQuery

Lucene.Net.Search.Query matching child documents.

Lucene.Net.Search.Filter parentsFilter

Lucene.Net.Search.Filter (must produce Lucene.Net.Util.FixedBitSet per-segment, like FixedBitSetCachingWrapperFilter) identifying the parent documents.

ScoreMode scoreMode

How to aggregate multiple child scores into a single parent score.

Methods

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CreateWeight(IndexSearcher)

Declaration
public override Weight CreateWeight(IndexSearcher searcher)
Parameters
Type Name Description
Lucene.Net.Search.IndexSearcher searcher
Returns
Type Description
Lucene.Net.Search.Weight
Overrides
Lucene.Net.Search.Query.CreateWeight(Lucene.Net.Search.IndexSearcher)
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Equals(Object)

Declaration
public override bool Equals(object obj)
Parameters
Type Name Description
System.Object obj
Returns
Type Description
System.Boolean
Overrides
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ExtractTerms(ISet<Term>)

Declaration
public override void ExtractTerms(ISet<Term> terms)
Parameters
Type Name Description
System.Collections.Generic.ISet<Lucene.Net.Index.Term> terms
Overrides
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GetHashCode()

Declaration
public override int GetHashCode()
Returns
Type Description
System.Int32
Overrides
Lucene.Net.Search.Query.GetHashCode()
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Rewrite(IndexReader)

Declaration
public override Query Rewrite(IndexReader reader)
Parameters
Type Name Description
Lucene.Net.Index.IndexReader reader
Returns
Type Description
Lucene.Net.Search.Query
Overrides
Lucene.Net.Search.Query.Rewrite(Lucene.Net.Index.IndexReader)
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ToString(String)

Declaration
public override string ToString(string field)
Parameters
Type Name Description
System.String field
Returns
Type Description
System.String
Overrides