You will need to make additional indexes for the associated models in the calling model to make this happen. For example:
class Business < ActiveRecord::Base
attr_accessible :name
has_many :services, :through => :professionals
searchable do
text :name #name in business column
text :services do # this one for full text search
services.map(&:service).compact.join(" ")
end
string :services , :multiple => true do #this one for exact searches
services.map(&:service).compact
end
end
end
After that you can do queries like:
Bussines.search do
with(:services, "some_service")
end.execute.results
Now you no longer have to do join on mysql tables to fetch data. You can just fetch data from the solr. This is one of biggest advantages of solr.
I hope this makes it clear. Fell free to drop a comment if you need more details.