I'm new to rails and I have this problem
I have three models, provider model, product model and categorie model, all models are related.
If you enter a product, you can select provider and categorie for this product.
I can not delete a provider or a categorie because they relate to product
But I can remove a product without problems
As I can manage to eliminate a provider or gategorie without affecting product?
class Categorie < ActiveRecord::Base
belongs_to :user
end
class Product < ActiveRecord::Base
belongs_to :user
belongs_to :provider
belongs_to :categorie
end
class Provider < ActiveRecord::Base
belongs_to :user
has_many :products
end
Thank!
You can use dependent: destroy on your has_many relationships so that when a provider with many products is deleted, the products are deleted as well:
class Provider < ActiveRecord::Base
has_many :products, dependent: :destroy
end
Use this gem for deleting purpose. It will soft delete entities https://github.com/rubysherpas/paranoia
Related
I'm trying to create an eCommerce shop. My main idea is every user can create their own store, and I have models like this:
model/user.rb:
class User < ApplicationRecord
has_one :store
end
model/store.rb:
class Store < ApplicationRecord
belongs_to :user
has_many :products
end
model/product.rb
class Product < ApplicationRecord
belongs_to :store
end
I don't know if the relationships between these models is good enough or I should modify them. And for further update, if user_1 add product sold by user_2 to his cart, I don't know what will the relationship be between these two users
Your models don't have a relationship between User and Product yet.
You can say User has_many: :products
and Product has_one: :user but this relationship would be incomplete.
The user-product relationship needs to be done through the store. That's where has_many: through comes in handy.
User has_many :products, through: :store
Product has_one :user, through: :store
In my app I have 3 model:
OrganizationType
Organization
OrganizationTypeLink
as you guess: my organization could perform more than one action, and this type of action's I want to link with organization...
And in controller I write so:
def create
#admin_organization = Organization.new(admin_organization_params)
#admin_organization.organization_type_links.build(organization_type_id: params[:organization_type_id], organization_id: #admin_organization.id)
if #admin_organization.save
....
And in model OrganizationTypeLink I see new rows in db, but how to store in Organization organization_type_link_id ? How could I store it in db?
I am new to RoR, so please give advice )
upd:
class Organization < ActiveRecord::Base
belongs_to :organization_type
has_many :organization_type_links, :dependent => :destroy
end
class OrganizationTypeLink < ActiveRecord::Base
belongs_to :organization
belongs_to :organization_type
end
class OrganizationType < ActiveRecord::Base
has_many :organizations
has_many :organization_type_links
end
how to store in Organization organization_type_link_id ? how could i store it in db?
The way you have currently defined associations in these 3 models: OrganizationType, Organization and OrganizationTypeLink
Organization has_many organization_type_links means that OrganizationTypeLink will have a foreign key named organization_id in it and not the other way round.
If you want to have organization_type_link_id in Organization then you would need to setup association as:
class Organization < ActiveRecord::Base
belongs_to :organization_type
belong_to :organization_type_link
end
class OrganizationTypeLink < ActiveRecord::Base
has_many :organizations, :dependent => :destroy
belongs_to :organization_type
end
I have two models, User and Product
class User < ActiveRecord::Base
has_and_belongs_to_many :products
end
class Product < ActiveRecord::Base
has_and_belongs_to_many :users
end
Now I want to make three lists for each user, products they've checked out recently, products that are in their shopping cart and products which they have bought. How do I make a distinction between these relations? Could I add some sort of type column to the relation table? And how could I then later check this type?
Thanks
If you and to add other columns to the relation table perhaps you should consider using has_many on both User and Products, then you can add your columns on Cart
class User < ActiveRecord::Base
has_many :carts
has_many :products, through: :carts
end
class Cart < ActiveRecord::Base
belongs_to :user
belongs_to :product
end
class Product < ActiveRecord::Base
has_many :carts
has_many :users, through: :carts
end
I'm a beginner in Rails and I have a problem with ActiveRecords associations.
I'm creating simple car rental service and I made the following associations:
class Client < ActiveRecord::Base
has_many :rentals
has_many :bookings
has_many :cars, :through => :rentals
has_many :cars, :through => :bookings
end
class Rental < ActiveRecord::Base
belongs_to :client, dependent: :destroy
has_one :car
end
class Booking < ActiveRecord::Base
belongs_to :client, dependent: :destroy
has_one :car
end
What I need is to have a car belonging to many bookings and rentals while every booking and rental can have only one car assigned.
class Car < ActiveRecord::Base
# belongs_to_many :bookings
# belongs_to_many :rentals
end
How should I do that?
If a car can have many bookings/rentals, but a booking/rental can only have one car, you're looking at a classic belongs_to/has_many situation. It looks like you're being tripped up by the distinction between belongs_to and has_one -- it's not a grammatical one, but a matter of where the foreign key column is located in your database.
belongs_to: "I am related to exactly one of these, and I have the foreign key."
has_one: "I am related to exactly one of these, and it has the foreign key."
has_many: "I am related to many of these, and they have the foreign key."
Note that has_one and has_many both imply there's a belongs_to on the other model, since that's the only option where "this" model has the foreign key. Note also that this means has_one should only be used when you have a one-to-one relationship, not a one-to-many.
Taking this into consideration, I would replace the has_one :car with belongs_to :car in both your Rental and Booking models, and place has_many :bookings and has_many :rentals in your Car model. Also ensure that your rentals and bookings tables have a car_id column; there should be no rental- or booking-related columns in your cars table.
Yes, there is a "belongs_to_many" in Rails, sort of. It's a little more work and you can't use generators with it. It's called a polymorphic association.
Even though you could make a car have many bookings & rentals, you could associate the car by making it belong to a polymorph such as rentable_vehicle. Your code would look like this
class Car < ActiveRecord::Base
belongs_to :rentable_vehicle, polymorphic: true
end
class Rental < ActiveRecord::Base
belongs_to :client, dependent: :destroy
has_many :cars, as: :rentable_vehicle
end
class Booking < ActiveRecord::Base
belongs_to :client, dependent: :destroy
has_many :cars, as: :rentable_vehicle
end
You can't do belongs_to_many. The closest you can really get is has_and_belongs_to_many, but I'm not sure that's what you want here - unless you can have multiple cars per rental/booking. Check out the guide for a full explanation.
I'd change it up like this:
class Rental < ActiveRecord::Base
belongs_to :client, dependent: :destroy
belongs_to :car
end
class Booking < ActiveRecord::Base
belongs_to :client, dependent: :destroy
belongs_to :car
end
class Car < ActiveRecord::Base
has_many :bookings
has_many :rentals
end
Also, I don't know how your rentals relate to bookings, but my immediate thought is that there should be some relationship between the two, because you probably can't have a rental without booking it, right?
I have a Store that has many Catalogs and in turn each catalog has many Products.
The Product and Catalog shares many to many relationship.
One product can belong to many catalogs and vice-verse.
So, my model definition goes like this:
class Store < ActiveRecord::Base
has_many :store_catalogs
has_many :catalogs, :through => :store_catalogs
end
class StoreCatalog < ActiveRecord::Base
belongs_to :store
belongs_to :catalog
end
class Catalog < ActiveRecord::Base
has_many :store_catalogs
has_many :stores, :through => :store_catalogs
has_and_belongs_to_many :product_set, :class_name => "Product"
end
class Product < ActiveRecord::Base
has_and_belongs_to_many :catalogs
end
Now, I would like to access all the products that belongs to a store.
How do I link those together so that I get that? please suggest.
I am trying out various combinations from the rails console to pull the data, not sure if the console itself limits the relation based querying by any chance(though i would like to believe it doesn't).
I think this should solve your problem
class Store < ActiveRecord::Base
has_many :catalogs
has_many :products, :through => :catalogs
end
class Catalog < ActiveRecord::Base
belongs_to :store
has_and_belongs_to_many :products
end
class Product < ActiveRecord::Base
has_and_belongs_to_many :catalogs
end
And then you just need a table in your database called catalogs_products with catalog_id and product_id to link the has_and_belongs_to_many association.
Then in order to get all the products from a store just do
Store.find(id).products