Models can associate in three main ways: one to many, one to one, and many to many.
This is tagged primarily in Ruby community. Models can associate in three main ways: one to many, one to one, and many to many.
Questions tagged [model-associations]
865 questions
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1 answer
Creating table entry with params hash and associated model(s) params hash
i want to do something like this:
user.items << Item.new(params[:item] , :computer => Computer.new(params[:computer] , :laptop => Laptop.new(params[:laptop])))
But this generates an error "wrong number of arguments (2 for 1)"!
serpent403
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votes
2 answers
Get id of intance Ruby on Rails
I am building an ruby app to book accommodations. So I would to put a form_with in the show action for the model Booking. Model Booking is a connection between is User model and Logement Model. To do a Booking a need user_id and logement_id, so I…
Wiilfredmuffins
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1 answer
How can I insert many records from Controller in rails?
I have Classroom model Like:
class Classroom < ApplicationRecord
has_many :students,dependent: :destroy
end
I have Student model Like:
class Student < ApplicationRecord
belongs_to :classroom, optional: true
validate…
bhadresh chotaliya
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votes
1 answer
Can't display categories under category type
I have two different models category and category type i just want to display categories under category type but i don't know how.
I’m using has_many and belongs_to association where the category has a foreign key 'categorytype_id'
I've tried but…
M.Mannai
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votes
1 answer
How do I set up associations for two different models to belong to one categories model
So I have these 3 models: Coupon, Place, and Category. I want to set up associations such that:
Category has both coupons and places associated with it
Coupon belongs to several categories
Place belongs to several categories.
How would I implement…
Christian Dziwornu
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- 6
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votes
1 answer
Unpermitted params error while creating records of grand-child records in grand-parent forms
I have three models Book_Room, Invoice, and Bill. Invoice belongs to BookRoom, and has many bills. the error is unpermitted params error for :invoice is thrown when i try to create Book Room after ive clearly asked to accept nested params
class…
Prince Abalogu
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votes
2 answers
Two layers of has_many/belongs_to
enter image description hereI'm writing a to-do list app. Each user can have multiple list categories, and each list category can contain multiple list items:
class User < ApplicationRecord
has_many :list_categories, dependent: :destroy
has_many…
mef27
- 379
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- 15
-1
votes
1 answer
Assocation and Generalization between two classes
Can anyone give me example of class B which inherits from A and there is association between them and what pattern uses such bonds?
I am referring to the situation where A is generalization of B and exists association bond between them on UML…
ssukienn
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votes
1 answer
Errors in class relationships in c++
I am quite new to the concept of class relationships and wrote a program to test it out. However, it is giving me some errors.
There are 5 header files for classes University,Dept,Teacher,Student and Course and a .cpp file involved. I have…
Syed Abdul Wahab
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votes
2 answers
Rails - One-direction table association - accessing data issue
I have two models:
class Order < ActiveRecord::Base
belongs_to :user
has_one :order_type
end
class OrderType < ActiveRecord::Base
belongs_to :order
end
my schema.rb:
create_table "order_types", force: :cascade do |t|
t.string "ort_name"
…
Michal
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votes
1 answer
Display content through ActiveRecord_Association_CollectionProxy
I have a Products model with a 'has_many' relationship to Microposts. Likewise, Microposts has a 'belongs_to' relationship to Products. throught this relationship I want to populate a row in table with all the available microposts for that product.…
Houghtonbrad
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- 4
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votes
1 answer
get count of has_many association in rails query
I have a two model. Post and `Comment'.
Post has_may comments.
Query:
I want to get the max count of comments in which post.
This should be done by rail query.
Vinay
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votes
1 answer
Relationship of SQL and NoSQL entities in Symfony
I use symfony on my web page, I want to use both mongodb and mysql in my database model, and i don't know how to link between a table on my sql and a document on mongodb.
Example: PERSON -- relation 1--n -- ADDRESS, where PERSON is a table on my…
user3598828
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votes
1 answer
rails Unizillaize constant in Association
I'm trying to find the relations between Surgeon and Appointments.
2.0.0-p195 :001 > surgeon = Surgeon.first
Surgeon Load (0.1ms) SELECT "surgeons".* FROM "surgeons" ORDER BY "surgeons"."id" ASC LIMIT 1
=> #
Papouche Guinslyzinho
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1 answer
Rails save data association models from single form
I have 3 table
User(id,email)
Client_Org(id,name)
Role(id,user_id,client_org_id,role) role:default "CD"
Form add new client organization
= form_for(@client_org,remote: true) do |f|
.post_errors
.form_add_email
=f.label :"Name of Client…
chinh
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