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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votes
2 answers
Multiple Model Associations to same table
My situation: I want to bring a HABTM and a hasOne relation working in the same model. unfortunatelly its not loading the groupleaders userinformation into the usergroups.
a user can have multiple usergroups
a usergroup can have one groupleader…
endo.anaconda
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2 answers
Cakephp inheritance of model associations
If I create a Model Car with some associations:
hasOne Driver
hasMany Wheel
And then create a Model Truck extending Car with
class Truck extends Car { ... }
is it normal that the associations from Car are not inherited from Truck?
What are the…
Martin Cup
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1 answer
What is the difference between :include and :through options in rails associations?
I don't understand in which case I should use the :include option instead of the :through option ?
For instance I can write my models like this :
Class Customer < ActiveRecord::Base
has_many :orders, :include => :line_items
end
class Order <…
Douglas
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1 answer
Ruby on rails active record associations
I need 2 models for my store:
Shoe
ShoeSize
According to my concept - one shoe can have several sizes (one model of shoes can be 34,35,36,37 size).
What types of associations should I use? What database table fileds do I need to create to support…
prosto.vint
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1 answer
many-to-many relationship in rails
I have the following models
class Order < ApplicationRecord
has_many :order_details
has_many :products, through: :order_details
end
class OrderDetail < ApplicationRecord
belongs_to :order
belongs_to :product
end
class Product <…
gaacode
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3 answers
OneToOne Association In JPA not working using Spring boot and spring data JPA
I am trying to implement the OneToOne association in JPA and trying to join two tables using spring boot and spring data JPA. I created one spring boot microservice and implemented the one to one association in my model. But when I am running code I…
Mr.DevEng
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1 answer
trying the rails model association
I'm not sure if this a best practices in terms of association. Anyone can help me
//post,rb
class Post < ApplicationRecord
belongs_to :user
has_one :location, through: :user
has_one :category, through: :user
has_one :type, through:…
Eric Luciano
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votes
2 answers
How to implement the class - Student relationship in c#?
I want to implement a system, which represents a ClassRoom- Student relationship. I want to impose the constraint that Each ClassRoom can have any number of students, but one student can be at only one ClassRoom.
I have created two classes -…
abhishek challa
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votes
2 answers
R: How to determine which variables are associated with a missing data field
I have a dataset that I am trying to understand why one specific variable (Var1) has blank values.
I have two questions, and I use R (and am a novice coder):
Var1 is 60% complete (field in entered with alphnumeric values, but 40% of entries are…
Ryan S
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2 answers
Ruby on Rails Model Associations, user admin and listing
I feel like this is a really easy question but i've been stuck for a while.
I have three models, user, listing and admin. Please how do i make both user and listing belong to admin?
