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Start your free trialAhmed Mohamed Fouad
11,735 PointsHow did models knew that "post_id" in comments model will be the foreign key for the primary key "id" in posts model ?
How did models knew that "post_id" in comments model will be the foreign key for the primary key "id" in posts model ?
is it from adding index when we were adding the "post_id" column to comments model ? or ... ?
1 Answer
Jay McGavren
Treehouse TeacherFrom the ActiveRecord documentation on belongs_to
:
By default this is guessed to be the name of the association with an
_id
suffix. So a class that defines abelongs_to :person
association will use"person_id”
as the default:foreign_key
.
If you want to use a different column name as the foreign key, you can pass the foreign_key
when you call the belongs_to
method.