LeftOuter Join capabilty in SOLR and dynamic field merge in response

I'm having different kind of entity in the index.
Entitity-1: id, doc_name, type, pinprojectid, documentid, content

Entity-2: id, proj_name,projtype,type,pinprojectid

where type is unique for every different entity e.g. Entity-1(type=Documents) & Entity-2(type=Projects).pinprojectid is common between two Entity.
Now im trying to search on type:Document AND content:"hello",
but the result do left outer join with Entity-2 based on join field say ( pinprojectid) and fetches few information like(projtype,proj_name) and display in the Entity-1 response.

Say Entity-1 search gives 12 result,but left-outer join field fetch matches with 10 result.
So the final output should be 12 with 10 doc containing extra merge fields through leftouter join.
This is very common in SQL.

One way to do this to process from client side with two separate call to SOLR server.But this functaility or enhancement or added feature needs to there in solr release in a generalized way.

Let me know if there is any other way to achieve the above scenario from server side of Solr in one call??