Apache Solr Reference Guide Covering Apache Solr 6.0

This parser takes a query that matches child documents and returns their parents. The syntax for this parser is
similar: q={!parent which=} . Again the parameter The parameter allPa
rents is a filter that matches only parent documents; here you would define the field and value that you used
to identify all parent documents. The parameter someChildren is a query that matches some or all of the
child documents. Note that the query for someChildren should match only child documents or you may get an
exception.
Again using the example documents above, we can construct a query such as q={!parent
which="content_type:parentDocument"}comments:SolrCloud. We get this document in response:
1
Solr has block join support
parentDocument
Using which
A common mistake is to try to filter parents with a
which filter, as in this bad example:
q={!parent which=" title:join "}comments:SolrCloud
Instead, you should use a sibling mandatory clause as a filter:
q= +title:join +{!parent which=" content_type:parentDocument"}comments:Sol
rCloud
Scoring
You can optionally use the score local parameter to return scores of the subordinate query. The values to use
for this parameter define the type of aggregation, which are avg (average), max (maximum), min (minimum), to
tal (sum). Implicit default is none which returns 0.0.
Boost Query Parser
BoostQParser extends the QParserPlugin and creates a boosted query from the input value. The main
value is the query to be boosted. Parameter b is the function query to use as the boost. The query to be boosted
may be of any type.
Examples:
Creates a query "foo" which is boosted (scores are multiplied) by the function query log(popularity) :
{!boost b=log(popularity)}foo
Creates a query "foo" which is boosted by the date boosting function referenced in ReciprocalFloatFunctio
n:
{!boost b=recip(ms(NOW,mydatefield),3.16e-11,1,1)}foo
Apache Solr Reference Guide 6.0
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