Railsでフォロー機能を作ろうとする時にエラーが生じてしまう

Question

railsでフォロー機能を実装したいために,以下のサイトを参考にして進めていきました

https://qiita.com/mitsumitsu1128/items/e41e2ff37f143db81897

#コード

#relationships マイグレーションファイル
class CreateRelationships < ActiveRecord::Migration[6.0]
  def change
    create_table :relationships do |t|
      t.references :user, foreign_key: true
      t.references :follow, foreign_key: { to_table: :users }

      t.timestamps

      t.index [:user_id, :follow_id], unique: true
    end
  end
end

#user.rb

class User < ApplicationRecord
  # Include default devise modules. Others available are:
  # :confirmable, :lockable, :timeoutable, :trackable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :validatable

  mount_uploader :image_name, ImageUploader

  has_many :relationships
  has_many :followings, through: :relationships, source: :follow
  has_many :reverse_of_relationships, class_name: 'Relationship', foreign_key: 'follow_id'
  has_many :followers, through: :reverse_of_relationships, source: :user


  validates :name, presence: true
  validates :profile, length: { maximum: 200 }

  def posts
    return Post.where(user_id: self.id)
  end

  def follow(other_user)
    unless self == other_user
      self.relationships.find_or_create_by(follow_id: other_user.id)
    end
  end

  def unfollow(other_user)
    relationship = self.relationships.find_by(follow_id: other_user.id)
    if relationship
      relationship.destroy
    end
  end

  def following?(other_user)
    self.followings.include?(other_user)
  end

end

#relationship.rb

class Relationship < ApplicationRecord
    belongs_to :user
    belongs_to :follow, class_name: "User"

    validates :user_id, presence: true
    validates :follow_id, presence: true
end

#relationships_controller.rb

class RelationshipsController < ApplicationController
	before_action :set_user
  
	def create
	  following = current_user.follow(@user)
	  if following.save
		flash[:success] = 'ユーザーをフォローしました'
		redirect_to @user
	  else
		flash.now[:alert] = 'ユーザーのフォローに失敗しました'
		redirect_to @user
	  end
	end
  
	def destroy
	  following = current_user.unfollow(@user)
	  if following.destroy
		flash[:success] = 'ユーザーのフォローを解除しました'
		redirect_to @user
	  else
		flash.now[:alert] = 'ユーザーのフォロー解除に失敗しました'
		redirect_to @user
	  end
	end
  
	private
	def
	  @user = User.find(params[:relationship][:follow_id])
	end
  
  end

#app/views/relationships/_follow_button.html.erb
<% unless current_user == user %>
  <% if current_user.following?(user) %>
    <%= form_for(current_user.relationships.find_by(follow_id: user.id), html: { method: :delete }) do |f| %>
      <%= hidden_field_tag :follow_id, user.id %>
      <%= f.submit 'Unfollow', class: 'btn btn-danger btn-block' %>
    <% end %>
  <% else %>
    <%= form_for(current_user.relationships.build) do |f| %>
      <%= hidden_field_tag :follow_id, user.id %>
      <%= f.submit 'Follow', class: 'btn btn-primary btn-block' %>
    <% end %>
  <% end %>
<% end %>

#routes.rb
Rails.application.routes.draw do

  devise_for :users, controllers: {
    registrarions: "users/registrations"
  }

  resources :users, only: [:show,:index]

  get '/' => "home#top"

  resources :posts

  resources :relationships, only: [:create, :destroy]



  # For details on the DSL available within this file, see https://guides.rubyonrails.org/routing.html
end

そしてユーザー詳細ページにフォローボタンを置こうと思い,
<%= render ‘relationships/follow_button’, user: @user %> をユーザー詳細ページに追加しました

#app/views/users/show.html.erb

<div class="main show-box">
  <div class="show-box-inner">
    <div class="show-header">
      <div class="show-header-item">
        <div class="show-left">
          <img src=<%= @user.image_name %> class="show-icon-image">
        </div>
        <div class="show-right">
          <div class="name-row">
            <p class="show-user-name"><%= @user.name %></p>
            <div class="row-left">
              <% if @user.id == current_user.id %>
                <%= link_to "プロフィールを編集", edit_user_registration_path, class: "edit-profile" %>
                <%= link_to "delete User", user_registration_path, {method: :delete, class: "delete-account"} %>
              <% end %>
            </div>
          </div>
          <p>プロフィール: <%= @user.profile %></p> 
        </div>
      </div>
    </div>

    <%= render ‘relationships/follow_button’, user: @user %> #追加

    <h2>投稿一覧</h2>
    <%= @user.posts.each do |post| %>
      <div class="posts-index-item">
        <div class="post-left">
          <img src=<%= post.user.image_name %> class="icon-image">
        </div>
        <div class="post-right">
          <%= link_to post.user.name, user_path(post.user.id), class: "change" %> 
          <%= link_to post.content, edit_post_path(post.id), class: "content" %>
        </div>
      </div>
    <% end %> 
  </div>
</div> 

その後ユーザー1でログインしているときにユーザー2の詳細ページ user.showにアクセスすると以下のエラーが生じてしまいます

#エラー内容

ActiveRecord::StatementInvalid in Users#show
Showing /home/riku/self_application/Rails/Theidea/app/views/relationships/_follow_button.html.erb where line #2 raised:

SQLite3::SQLException: no such column: relationships.user_id
Extracted source (around line #36):
34
35
36
37
38
39
              

  def following?(other_user)
    self.followings.include?(other_user)
  end

end

Trace of template inclusion: #<ActionView::Template app/views/users/show.html.erb locals=[]>

Rails.root: /home/riku/self_application/Rails/Theidea

Application Trace | Framework Trace | Full Trace
app/models/user.rb:36:in `following?'
app/views/relationships/_follow_button.html.erb:2
app/views/users/show.html.erb:23

following?メソッドに問題があると書かれていますがどこが問題があるのかわかりません...
どなたかご享受お願いします

Answer 1

SQLite3::SQLException: no such column: relationships.user_id

「relationshipsテーブルに、user_idカラムがないよ」と出ているので、まずは

• relationshipsテーブルが作られているか

• user_id という名前のカラムがあるか

を確認してみると良いのではないかと思います。