Package org.apache.solr.search.join

Class ScoreJoinQParserPlugin

java.lang.Object

org.apache.solr.search.QParserPlugin

org.apache.solr.search.join.ScoreJoinQParserPlugin

All Implemented Interfaces:

NamedListInitializedPlugin

public class ScoreJoinQParserPlugin
extends QParserPlugin

Create a query-time join query with scoring. It just calls JoinUtil.createJoinQuery(String, boolean, String, Query, org.apache.lucene.search.IndexSearcher, ScoreMode). It runs subordinate query and collects values of "from" field and scores, then it lookups these collected values in "to" field, and yields aggregated scores. Local parameters are similar to JoinQParserPlugin {!join} This plugin doesn't have its own name, and is called by specifying local parameter {!join score=...}.... Note: this parser is invoked even if you specify score=none .
Example:q={!join from=manu_id_s to=id score=total}foo

• from - "foreign key" field name to collect values while enumerating subordinate query (denoted as foo in example above). it's better to have this field declared as type="string" docValues="true". note: if docValues are not enabled for this field, it will work anyway, but it costs some memory for UninvertingReader. Also, numeric doc values are not supported until LUCENE-5868. Thus, it only supports DocValuesType.SORTED, DocValuesType.SORTED_SET, DocValuesType.BINARY.
• fromIndex - optional parameter, a core name where subordinate query should run (and from values are collected) rather than current core.
  Example:q={!join from=manu_id_s to=id score=total fromIndex=products}foo
• to - "primary key" field name which is searched for values collected from subordinate query. it should be declared as indexed="true". Now it's treated as a single value field.
• score - one of ScoreMode: none,avg,total,max,min. Capital case is also accepted.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	CHECK_ROUTER_FIELD
static final String	SCORE
static final String	USE_CROSSCOLLECTION

Fields inherited from class org.apache.solr.search.QParserPlugin

DEFAULT_QTYPE, standardPlugins

Constructor Summary

Constructors

Constructor	Description
ScoreJoinQParserPlugin()

Method Summary

Modifier and Type	Method	Description
static org.apache.lucene.search.Query	createJoinQuery(org.apache.lucene.search.Query subQuery, String fromField, String toField, org.apache.lucene.search.join.ScoreMode scoreMode)	A helper method for other plugins to create single-core JoinQueries
QParser	createParser(String qstr, org.apache.solr.common.params.SolrParams localParams, org.apache.solr.common.params.SolrParams params, SolrQueryRequest req)	Creates the QParser.
static String	getCoreName(String fromIndex, CoreContainer container, SolrCore toCore, String toField, String fromField, org.apache.solr.common.params.SolrParams localParams)	Returns a String with the name of a core.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.solr.util.plugin.NamedListInitializedPlugin

init

Field Details

USE_CROSSCOLLECTION

public static final String USE_CROSSCOLLECTION

See Also:

• Constant Field Values

SCORE

public static final String SCORE

See Also:

• Constant Field Values

CHECK_ROUTER_FIELD

public static final String CHECK_ROUTER_FIELD

See Also:

• Constant Field Values

Constructor Details

ScoreJoinQParserPlugin

public ScoreJoinQParserPlugin()

Method Details

createParser

public QParser createParser(String qstr,
 org.apache.solr.common.params.SolrParams localParams,
 org.apache.solr.common.params.SolrParams params,
 SolrQueryRequest req)

Description copied from class: QParserPlugin

Creates the QParser.

Specified by:

createParser in class QParserPlugin

See Also:

• QParser(String, SolrParams, SolrParams, SolrQueryRequest)

getCoreName

public static String getCoreName(String fromIndex,
 CoreContainer container,
 SolrCore toCore,
 String toField,
 String fromField,
 org.apache.solr.common.params.SolrParams localParams)

Returns a String with the name of a core.

This method searches the core with fromIndex name in the core's container. If fromIndex isn't the name of a collection or alias it returns fromIndex without changes. If fromIndex is the name of an alias but the alias points to multiple collections it throws SolrException.ErrorCode.BAD_REQUEST because multiple shards not yet supported.

Parameters:

fromIndex - name of the index

container - the core container for searching the core with fromIndex name or alias

toCore - core which it joins to ie executing this request

toField - to side field

fromField - from side field

localParams - local params for this qparser invocation

Returns:

the string with name of core

createJoinQuery

public static org.apache.lucene.search.Query createJoinQuery(org.apache.lucene.search.Query subQuery,
 String fromField,
 String toField,
 org.apache.lucene.search.join.ScoreMode scoreMode)

A helper method for other plugins to create single-core JoinQueries

Parameters:

subQuery - the query to define the starting set of documents on the "left side" of the join

fromField - "left side" field name to use in the join

toField - "right side" field name to use in the join

scoreMode - the score statistic to produce while joining

See Also:

• JoinQParserPlugin.createJoinQuery(Query, String, String, String)