ruby on rails - Is a migration necessary for generating an ID in a has_many/belongs_to relationship? -

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i have rails app 2 related classes. pet has_many toys, , toy belongs_to pet.

in order have index of toys pets (meaning every toy want have index identifier stating pet belongs to), need add migration adding pet_id column each toy (to toys table), or automatically done rails has_many-belongs_to relationship?

you need add pet_id column toys table if table doesn't have one. has_many , belongs_to create methods ease writing code.


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