activerecord - How to retrieve all related objects from an existing selection set in Rails -

in rails app have 2 models related via has_many , belongs_to associations:

class entity < activerecord::base   has_many :applicants end class applicant < activerecord::base   belongs_to :entity end 

i'm using searchkick first select entities - details of don't matter, given existing collection of entity objects, how can retrieve of related applicant objects?

# select entities (in app i'm using searchkick run search) entities = entity.search params[:query]  # find applicants related selected entities applicants = entities.??? 

this works, slow given large selection:

# retrieve applicants related selected entities applicants = [] entities.each |entity|   applicants += entity.applicants end 

is there rails short-hand retrieve applicants related selected entities?

other things i've tried:

entities.class => entity::activerecord_relation  entities.applicants => #error entities.applicant_ids => #error 

like this?

applicant.joins(:entity).where("entities.id < ?", 1000)