update or delete on table "x" violates foreign key constraint "fk_rails_5a7b40847a" on table "x" [duplicate]
It depends what you want to do with the post's comments on its deletion. In case you want to delete them on cascade, for example:
post.rbhas_many :comments, dependent: :destroy
Update the below line in your Post model as below
has_many :comments, dependent: :destroy You have to mention dependent: :destroy in your Post model. So when any post get to deleted by post.destroy, It deletes the all dependent records of Comment model.
Hope this will resolve your issue
It's because you have a constraint in your database.
I presume that the foreign key post_id in table comments must exist in the associated table posts.
That is certainly because you specify the foreign key relation in the migration with rails g model Comment post:references.
You have to specify what to do with associated models on deletion :
class Post < ActiveRecord::Base has_many :comments, dependent: :destroy # destroy associated commentsendThen call method post.destroy instead of post.delete on your record
See has_many for other options