Questions tagged [has-many-through]
1523 questions
3
votes
1 answer
Rails namespaced has_many through missing column
In my rails project I have a namespaced has_many through relation
Scheme
models/school/contact.rb
class School::Contact < ApplicationRecord
belongs_to :school, class_name: '::School'
has_many :school_contact_emails, class_name:…
Gianmarco Digiacomo
- 312
- 3
- 8
3
votes
2 answers
Rails - modeling multiple many to many relationships
I have the following use cases for creating an app that handles courses;
Class A is taught by Curt in Bos on 11/1
Class A is taught by Curt in NY on 10/19
Class A is taught by Jane in SF on 12/5
Class A is taught by Jane in Bos on 11/1
What's the…
Arash Hadipanah
- 115
- 9
3
votes
2 answers
why does column trades.item_id not exist?
I have a relationship model in which two Users can enter into a Trade for the exchange of two Items.
class User < ActiveRecord::Base
has_many :owned_items, class_name: "Item"
has_many :trades_received, class_name: "Trade", through: :owned_items,…
calyxofheld
- 1,538
- 3
- 24
- 62
3
votes
3 answers
Rails 5 - how to dynamically add to the form a nested object using autocomplete
I have 3 models - team, user and team_user (has_namy: through). In the form of edit and new team to do the ability to dynamically add members of this team with autocomplete input.
app/models/user.rb
class User < ApplicationRecord
has_many…
Nikolay Lipovtsev
- 657
- 1
- 6
- 15
3
votes
1 answer
Seemingly redundant ActiveRecord has_many definition
I've been applying has and belongs to many style associations to a project I've been working on, but because I wanted to capture extra information in my join model, I'm implicitly setting it up via the more elaborate belongs_to/has_many approach…
Joost Schuur
- 4,417
- 2
- 24
- 39
3
votes
1 answer
How do I save and update attributes in a join table in Rails 4 HMT association?
I have a has_many through join table setup for a recipe app where Ingredient and Meal connect through MealIngredient. Within MealIngredient, I have meal_id, ingredient_id, and amount.
My question is: How can I save and update the amount column in…
don_Bigote
- 896
- 7
- 33
3
votes
3 answers
How to validate presence of associated records in case of has_many, through: association?
There are models with has has_many through association:
class Event < ActiveRecord::Base
has_many :event_categories
has_many :categories, through: :event_categories
validates :categories, presence: true
end
class EventCategory <…
y.bregey
- 1,469
- 1
- 12
- 21
3
votes
2 answers
Rails 4 nested form with has_many, through and multiple select
I have a problem with nested form and has_many relation. Bussiness case: there are laboratories and their suppliers. Suppliers can be shared between labs.
Models
class Lab < ActiveRecord::Base
has_many :lab_suppliers
has_many :suppliers,…
Michal
- 139
- 3
- 14
3
votes
0 answers
Multiple has_many association through same table in Rails
I have following database schema:
I want to be able to do something like this:
dog.head << Feature.new(...)
dog.tail << Feature.new(...)
I am new to Rails, so I am not always sure by 100% what I am writing, but I tried following declaration of…
spacemonkey
- 19,664
- 14
- 42
- 62
3
votes
2 answers
How to access ':has_many :though' join table data when using to_json?
I have three models (simplified here):
class Child < ActiveRecord::Base
has_many :childviews, :dependent => :nullify
has_many :observations, :through => :childviews
end
class Childview < ActiveRecord::Base
belongs_to :observation
…
qryss
- 642
- 1
- 5
- 9
3
votes
1 answer
Obtaining records where a certain condition is satisfied with two has_many :through
Let's say I have 3 models in my Rails app... Establishment, WasteType and EstablishmentWaste... My problem is that I want to get all establishments associated with a certain wastetype. This normally would be done with…
Patricio Sard
- 2,092
- 3
- 22
- 52
3
votes
2 answers
Rails 4 + Pundit : join model authorization in has_many :through association
In my Rails app, there are 3 models, defined by a has_many :through association:
class User < ActiveRecord::Base
has_many :administrations
has_many :calendars, through: :administrations
end
class Calendar < ActiveRecord::Base
has_many…
Thibaud Clement
- 6,607
- 10
- 50
- 103
3
votes
1 answer
Rails 4: routing for has_many :through association
I have three models:
class User < ActiveRecord::Base
has_many :administrations
has_many :calendars, through: :administrations
end
class Calendar < ActiveRecord::Base
has_many :administrations
has_many :users, through:…
Thibaud Clement
- 6,607
- 10
- 50
- 103
3
votes
1 answer
Sortable List with Rails Namespaces & Railscasts 147 Error: Invalid request: Invalid HTTP format, parsing fails
I am building a sortable functionality for a join table in Rails. I have 3 models, Food, User, User_Food. Food is a prepopulated table of common foods. A user adds their favorites to User_Food. I am trying to let the user use JQuery Sortable to…
NothingToSeeHere
- 2,253
- 5
- 25
- 57
3
votes
3 answers
rails eager load has_many through join table
My development environment is on Rails 4.1 and postgresql
I've 3 models with has_many through relationship:
class Item < ActiveRecord::Base
has_many :item_parts
has_many :parts, through: :item_parts
end
class Part < ActiveRecord::Base
…
harlock975
- 51
- 4