PG::ForeignKeyViolation: ERROR: update or delete on table 我不知道为什么

Question

I am contacting you because I have a rather important problem. And that despite my research on stackoverflow or elsewhere, I can not correct after a lot of testing and a lot of tinkering.

I practice by making a site where you can list secrets that I call "gossip".

There is a button that allows you to delete a "gossip".

But when I want to remove the "gossip"

I have an error message which is the following:

From what I understand, it is my relationship between the tables that is causing the problem. I therefore attach you my code of these tables in questions:

 class Tag < ApplicationRecord has_many:gossips, through: :tag_join_gossip, dependent: :destroy validates:title, presence: true end

 class TagJoinGossip < ApplicationRecord belongs_to:gossip belongs_to:tag, optional: true end

 class Gossip < ApplicationRecord belongs_to:user, optional: true has_many:likes has_many:tags, through: :tag_join_gossip has_many:comments validates:title, presence: true, length: {minimum: 3, maximum: 14} validates:content, presence: true, length: {minimum: 1} end

My controller:

 class GossipController < ApplicationController before_action:authenticate_user def index @id = params[:id] @gossips = Gossip.all end def show @id= params[:id] @gossip = Gossip.find(params[:id]) @comments = Gossip.find(params[:id]).comments @comment = Comment.new(content: params['content'], gossip_id: 1, gossip_id: @gossip,user_id: 1) end def new @gossip = Gossip.new end def create @gossip = Gossip.new(title: params['title'], content: params['content']) @gossip.user = User.find_by(id: session[:user_id]) if @gossip.save flash[:success] = "Gossip bien créé:" redirect_to welcome_index_path else flash[.danger] = "Nous n'avons pas réussi à créer le potin pour la (ou les) raison(s) suivante(s) " render new_gossip_path end end def edit @gossip = Gossip:find(params[.id]) end def update @gossip = Gossip:find(params[.id]) gossip_params = params:require(.gossip):permit(,title: .content) if @gossip:update(gossip_params) flash[:success] = "Gossip bien modifié:" redirect_to welcome_index_path else render,edit flash[.danger] = "Nous n'avons pas réussi à modifier le potin. le titre doit faire 3 lettres minimum et vous devez remplir le contenu:" end end def destroy @gossip = Gossip.find(params[:id]) @gossip.destroy redirect_to welcome_index_path end end private def authenticate_user unless current_user flash[:danger] = "Veuillez vous connecter." redirect_to new_session_path end end

Maybe there are other files that can be of interest so I put my project's github here: https://github.com/MC4517/Projet-THP-GOSSIP-J1

I've been on it all day, I'm starting to lose my mind lol.

Thank you very much for those who venture into my problem, although I think it must be easy for a large part of you!

Answer 1

You have a record with a foreign key (TagJoinGossip) referencing the record you want to destroy (Gossip). Adding dependent: :destroy to the has_many association should solve it.

 Class Gossip < ApplicationRecord
 
     has_many :tags, through: :tag_join_gossip, dependent: :destroy