The cartesianProduct Stream can be wrapped around the stream with the multi-value field. The cartesianProduct function is available in Solr 6.6 but since this was a late addition the documentation does not appear to Solr 7.0.
Here is a link to the docs in github: https://github.com/apache/lucene-solr/blob/branch_7_0/solr/solr-ref-guide/src/stream-decorators.adoc The first stream decorator is the docs the cartesianProduct. Since you can't sort on the multi-valued field though you'll have use a hashJoin to do the join. Joel Bernstein http://joelsolr.blogspot.com/ On Wed, Sep 6, 2017 at 4:08 AM, Marc Röttig <marc.roet...@vico-research.com> wrote: > Dear SOLR users, > > I want to use streaming expression innerJoin using a multi-valued field to > do the join by equality, that is having any child documents (of type > "child") and > one parent document (of type "parent") join these according to equality of > id_s and children_ids > > Parent > * id_s = "p123" > * type_s = "parent" > * children_ids_ss = "c1,c2" > > Child > * id_s = "c1" > * type_s = "child" > > Child > * id_s = "c2" > * type_s = "child" > > innerJoin( > search(collection,q="type_s:child",fl="id_s",sort="id_s ASC"), > search(collection,q="type_s:parent",fl="id_s,children_ids_ss",sort="id_s > ASC"), > on="id_s=children_ids_ss" > ) > > This seems to be impossible, I am getting the following exception > "java.util.ArrayList cannot be cast to java.lang.Comparable". Using a > GraphQuery with from and to > this relationship traversal along multi-valued fields worked (however not > between shards, this is why I switched to streaming expressions). > > Is there any mechanism to flatten the tuples with the multi-valued field > into new tuples with single-valued fields to get the join working ? Or any > other tweak. > > Note: The relationship between Parent and Child is many-to-many, thus > moving the foreign-keys to the children as single-valued fields is not > possible. > > The issue is related tot he following issue: http://lucene.472066.n3. > nabble.com/Using-multi-valued-field-in-solr-cloud-Graph- > Traversal-Query-td4324379.html > > Thanks a lot in advance for any assistance, > Marc > > > Dr. Marc Röttig > Software Developer > EMail: marc.roet...@vico-research.com > Telefon: +49(0)711. 78 78 29-290 > Fax +49(0)711. 78 78 29-10 > > VICO Research & Consulting GmbH > Friedrich-List-Strasse 46 / 70771 Leinfelden-Echterdingen > > Homepage: www.vico-research.com/ > Blog: www.vico-research.com/expert-talk > Twitter: www.twitter.com/vico_news > Facebook: www.facebook.com/vico.friend > Sitz der Gesellschaft: Leinfelden-Echterdingen > Amtsgericht Stuttgart, HRB 720896 > Geschäftsführer: Marc Trömel > >
