I'm having some problems with ruby on rails, specifically setting up a many-to-many connection with deal and event through deal_event. I've checked out several similar stackoverflow questions and even http://guides.rubyonrails.org/ but I'm still not getting something..
Here are my models:
deal.rb
class Deal < ActiveRecord::Base
has_many :deal_events
has_many :events, :through => "deal_events"
attr_accessible :approved, :available, :cents_amount, :dollar_amount, :participants, :type
end
event.rb
class Event < ActiveRecord::Base
has_many :deal_events
has_many :deals, :through => "deal_events"
attr_accessible :day, :image, :description, :location, :title, :venue, :remove_image
end
deal_event.rb
class DealEvent < ActiveRecord::Base
belongs_to :deal
belongs_to :event
end
And here are my migration files:
20130102150011_create_events.rb
class CreateEvents < ActiveRecord::Migration
def change
create_table :events do |t|
t.string :title, :null => false
t.string :venue
t.string :location
t.text :description
t.date :day
t.timestamps
end
end
end
20130112182824_create_deals.rb
class CreateDeals < ActiveRecord::Migration
def change
create_table :deals do |t|
t.integer :dollar_amount
t.integer :cents_amount
t.integer :participants
t.string :type, :default => "Deal"
t.integer :available
t.string :approved
t.timestamps
end
end
end
20130114222309_create_deal_events.rb
class CreateDealEvents < ActiveRecord::Migration
def change
create_table :deal_events do |t|
t.integer :deal_id, :null => false
t.integer :event_id, :null => false
t.timestamps
end
end
end
After I seed my database with one deal and one event, I go into the console and type in
deal = Deal.first # ok
event = Event.first # ok
DealEvent.create(:deal => deal, :event => event) # Error: ActiveModel::MassAssignmentSecurity::Error: Can't mass-assign protected attributes: deal, event
deal.events # Error: ActiveRecord::HasManyThroughAssociationNotFoundError: Could not find the association "deal_events" in model Deal
Any idea on what I'm doing wrong for these two errors to be popping up? Thanks.
You'll need this line in your DealEvent model:
attr_accessible :deal, :event
Although if it's just a relationship table (which it looks like) then you don't create the relationship that way. Use nested forms and the like.
Related
I have two models :
class Settlement < ActiveRecord::Base
set_primary_key :settlement_identifier
has_many :streets
attr_accessible :city, :name, :service_available, :zip, :country_id,: settlement_identifier
end
class Street < ActiveRecord::Base
belongs_to :settlement, foreign_key: "settlement_identifier"
attr_accessible :name, :settlement_identifier, :street_identifier
end
Because I am doing import for streets and settlements, I need to point streets via settlement_identifier, not settlement_id .
When I do
Street.first.settlement #it compare settlement_identifiers from both tables
But when try to get streets from single settlement like :
Settlement.first.streets
It throws an error
SELECT "streets".* FROM "streets" WHERE "streets"."settlement_id" = 4263
ActiveRecord::StatementInvalid: PG::Error: ERROR: column streets.settlement_id does not exist .
I want that query to be :
SELECT "streets".* FROM "streets" WHERE "streets"."settlement_identifier" = 4263
Any help ?
I solved this problem. Here is solution below :
class CreateSettlements < ActiveRecord::Migration
def change
create_table :settlements, primary_key: :settlement_identifier, id: :false do |t|
t.string :name
t.string :zip
t.string :city
t.string :service_available
t.integer :country_id
t.timestamps
end
end
def down
drop_table :settlements
end
end
Here I set primary_key in my migration to settlement_identifier, and set id to false
Also, my Street migration is:
class CreateStreets < ActiveRecord::Migration
def change
create_table :streets do |t|
t.string :name
t.integer :settlement_identifier
t.string :street_identifier
t.timestamps
end
end
end
So, Street has reference to Settlement via settlement_identifier .
Settlement model :
class Settlement < ActiveRecord::Base
has_many :streets, foreign_key: "settlement_identifier"
attr_accessible :city, :name, :service_available,:settlement_identifier
end
Street model :
class Street < ActiveRecord::Base
belongs_to :settlement, foreign_key: "settlement_identifier"
attr_accessible :name, :settlement_identifier, :street_identifier
end
I tried to set primary_key on Settlement model but that didn't work.
This works fine for me. If anyone have another solution, please put comment or code example.
I have a model called cause.rb which has a scope called pesquisa that I want to query in the table causes, fields that are references to other tables. I want to call the table places which have a field called city from the model cause.
Causes table:
class CreateCauses < ActiveRecord::Migration
def change
create_table :causes do |t|
t.string :title, null: false
t.text :description, null: false
t.boolean :anonymous, default: false
t.integer :count_likes, default: 0
t.integer :count_dislikes, default: 0
t.integer :count_visits, default: 0
t.references :user
t.references :category
t.timestamps
end
add_index :causes, :user_id
add_index :causes, :category_id
end
end
class AddPlaceIdToCauses < ActiveRecord::Migration
def change
add_column :causes, :place_id, :integer
end
end
Places table:
class CreatePlaces < ActiveRecord::Migration
def change
create_table :places do |t|
t.string :description
t.decimal :latitude
t.decimal :longitude
t.references :city
t.timestamps
end
add_index :places, :city_id
end
end
Here is the scope:
scope :pesquisa, ->(pesquisa) { where("cause.place.city like :p or category_id like :p ", p: "%#{pesquisa}%") }
default_scope :order => "id desc"
How do I resolve this problem? I try this above cause.place.city to call the city in the table places but nothing happens.
I have a Post model that has a polymorphic association with a Vote model:
post.rb:
class Post < ActiveRecord::Base
attr_accessible :title, :content, :total_votes
belongs_to :user
has_many :votes, :as => :votable, :dependent => :destroy
end
vote.rb
class Vote < ActiveRecord::Base
belongs_to :votable, :polymorphic => true
belongs_to :user
before_create :update_total
protected
def update_total
self.votable.total_votes ||= 0
self.votable.total_votes += self.polarity
end
end
As you can see in vote.rb I want to accomplish the following:
Each time an instance of Vote is created, I want to update the total_votes column of the votable model instance (in this case an instance of Post).
But nothing happens, when I create a vote for a post with post.votes.create(:polarity => 1), the total_votes column of the post still being nil.
Any suggestions to fix this?
EDIT:
This didn't work either:
class Vote < ActiveRecord::Base
belongs_to :votable, :polymorphic => true
belongs_to :user
before_create :update_total
protected
def update_total
self.votable.total_votes ||= 0
self.votable.total_votes += self.polarity
self.votable.save!
end
end
schema.rb:
create_table "posts", :force => true do |t|
t.string "content"
t.integer "user_id"
t.datetime "created_at"
t.datetime "updated_at"
t.string "title"
t.integer "comments_count", :default => 0, :null => false
t.integer "total_votes"
end
When you create the Vote object, the Post object already exists. You update it, but you don't save it. Try with the following code:
def update_total
self.votable.total_votes ||= 0
self.votable.total_votes += self.polarity
self.votable.save!
end
I am struggling with a polymorphic many-to-many association in rails 3.
My Article model looks like this:
class Article < ActiveRecord::Base
has_many :article_tags
has_many :people, :through => :article_tags, :source => :taggable, :source_type => :person
end
My ArticleTag model looks like this:
class ArticleTag < ActiveRecord::Base
belongs_to :article
belongs_to :taggable, :polymorphic => true
end
My Person model looks like this:
class Person < ActiveRecord::Base
has_many :article_tags, :as => :taggable
end
Finally, my Organization model looks like this:
class Organization < ActiveRecord::Base
has_many :article_tags, :as => :taggable
end
I have a schema which looks like this:
ActiveRecord::Schema.define(:version => 20110322234836) do
create_table "article_tags", :force => true do |t|
t.integer "taggable_id"
t.string "taggable_type"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "articles", :force => true do |t|
t.string "title"
t.text "content"
t.date "published_on"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "people", :force => true do |t|
t.string "first_name"
t.string "last_name"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "organizations", :force => true do |t|
t.string "title"
t.datetime "created_at"
t.datetime "updated_at"
end
end
I was hoping that this would allow me to create people and organizations relationships from my articles like this:
Article.create!
Article.first.people.create!
and hopefully to be able to access it the other way afterwards by
Person.first.articles
Unfortunately I get an error when I try to add a person this way:
Article.first.people.create!
NameError: uninitialized constant Article::person
.../base.rb:1199:in `compute_type'
.../reflection.rb:162:in `klass'
.../association_collection.rb:157:in `transaction'
.../has_many_through_association.rb:41:in `create_record'
.../has_many_through_association.rb:13:in `create!
Any help would be very much appreciated I've tried many alternatives but with no success.
I actually just had to some something similar to this recently. It looks like most of your code is right although in mine for the first section I would try changing do this:
class Article < ActiveRecord::Base
has_many :article_tags
has_many :people, :through => :article_tags, :source => :taggable, :source_type => "Person"
end
Also you can't do: Article.first.people.create({:name => "Tim"})
You would have to assign it to a variable first:
article = Article.first
article.people.create({:name => "Tim"})
Let me know if this works for you. I just skimmed through. If it doesn't i can double check my code again and see if there are any other differences.
How can i give composite primary key in Rails without any gem?
My first table in migration file:
class CreateUsers < ActiveRecord::Migration
def self.up
create_table :users do |t|
t.string :userid
t.string :name
t.string :address
t.timestamps
end
end
def self.down
drop_table :users
end
end
My second table in migration file:
class CreateProjects < ActiveRecord::Migration
def self.up
create_table :projects do |t|
t.string :title
t.string :description
t.timestamps
end
end
def self.down
drop_table :projects
end
end
In my schema file:
ActiveRecord::Schema.define(:version => 20110222044146) do
create_table "projects", :force => true do |t|
t.string "title"
t.string "description"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "users", :force => true do |t|
t.string "userid"
t.string "name"
t.string "address"
t.datetime "created_at"
t.datetime "updated_at"
end
end
Now I want to create a table called User_has_project in which I will refer to User and Project that means will have 2 foreign keys.
So I tried like this:
class CreateUser_has_projects < ActiveRecord::Migration
def self.up
create_table :user_has_projects do |t|
t.references :User
t.references :Project
t.boolean :status
t.timestamps
end
end
def self.down
drop_table :users
end
end
Now how can I set combination of user_id and project_id as a primary key in user_has_projects?
It looks like you're trying to specify a many-many relationship between Users and Projects, with an additional field on the relationship itself.
The way you're currently doing isn't the Rails way of doing things - especially with the concept of a composite primary key.
The Rails/ActiveRecord way of doing this sort of relationship modelling is to have a third model that describes the relationship between User and Project. For the sake of example, I'm going to call it an Assignment. All you need to do is re-name your user_has_projects table to assignments like so:
class CreateAssignments < ActiveRecord::Migration
def self.up
create_table :assignments do |t|
t.references :user
t.references :project
t.boolean :status
t.timestamps
end
end
def self.down
drop_table :assignments
end
end
And then, in your model files:
# app/models/user.rb
class User < ActiveRecord::Base
has_many :assignments
has_many :projects, :through => :assignments
end
# app/models/assignment.rb
class Assignment < ActiveRecord::Base
belongs_to :user
belongs_to :project
end
# app/models/project.rb
class Project < ActiveRecord::Base
has_many :assignments
has_many :users, :through => :assignments
end
You can read more about this here: http://guides.rubyonrails.org/association_basics.html#the-has_many-through-association