has-one – Tarik Billa

Difference between has_one and belongs_to in Rails? [duplicate]

February 7, 2023 by Tarik

No, they are not interchangable, and there are some real differences. belongs_to means that the foreign key is in the table for this class. So belongs_to can ONLY go in the class that holds the foreign key. has_one means that there is a foreign key in another table that references this class. So has_one can … Read more

Rails: Using build with a has_one association in rails

November 18, 2022 by Tarik

The build method signature is different for has_one and has_many associations. class User < ActiveRecord::Base has_one :profile has_many :messages end The build syntax for has_many association: user.messages.build The build syntax for has_one association: user.build_profile # this will work user.profile.build # this will throw error Read the has_one association documentation for more details.