database - Rails inverse_of doesn't work with conditions -

here models:

class flight < activerecord::base   has_many :seats, dependent: :destroy, inverse_of: :flight end  class seat < activerecord::base   belongs_to :flight, inverse_of: :seats end 

it seems inverse_of works well, when i'm using conditions doesn't work:

f1 = flight.first s1 = f1.seats.first s2 = f1.seats.second s3 = f1.seats.where(id: 0..1000000).third  s1.flight.equal? s2.flight => true s1.flight.equal? s3.flight => false 

what explains this? how can make work?

s1.flight.equal? s2.flight => true 

the above yields true because s1.flight , s2.flight refer the exact same ruby object.

s1.flight.equal? s3.flight 

here, s1.flight , s3.flight refer different ruby objects. both contain same record data (including same :id value)

the problem you're using ruby's equal? method, when should using rails' == or eql? comparators.

from the ruby object docs == (aliased eql? , equal?)

equality — @ object level, == returns true if obj , other same object. typically, method overridden in descendant classes provide class-specific meaning.

unfortunately, equal? variation not overridden in activerecord::base. the rails docs == (aliased eql?):

returns true if comparison_object same exact object, or comparison_object of same type , self has id , equal comparison_object.id.

you'll find has nothing :inverse_of. simple example can try

f1 = flight.all.first f2 = flight.all.first  f1.eql? f2 => true  f1 == f2 => true  f1.equal? f2 # direct object comparison (skips activerecord::base) => false