I have two basic models:
class Case < ActiveRecord::Base
has_many :contacts
end
class Contact < ActiveRecord::Base
belongs_to :case
belongs_to :contactable, :polymorphic => true, :foreign_key => :contactable_id
end
I also have quite a few models that are "sub types" of the Contact model:
class Attorney < ActiveRecord::Base
has_one :contact, as: :contactable, dependent: :destroy
accepts_nested_attributes_for :contact
end
class Client < ActiveRecord::Base
has_one :contact, as: :contactable, dependent: :destroy
accepts_nested_attributes_for :contact
end
I used polymorphic associations instead of STI because I don't want one table to store all the fields, which can get a little slow and overwhelming.
I am wondering if the has_many :contacts line from the Case model is correct. I try to use it in my console, but it doesn't really work the way I expected. Am I missing something?
I basically want an association where a Case can have many Contacts and a contact can belong to many cases. The contact can be of any type (Attorney or Client or Contact by itself). I was hoping it was as easy as case has_many :contacts
Related
Let's say I have three models: Organization, Skills and Assessments.
Can an Assessment belong to two different Organizations, via different relations?
For example, an assessment may have happened at organization A, but was based on a skill belonging to organization B.
Below are my models and associations:
class Organization < ActiveRecord::Base
has_many :checklists
has_many :levels, :through => :checklists
has_many :sections, :through => :levels
has_many :skills, :through => :sections
has_many :assessments_using_own_checklists, :through => :skills, :source => :assessments
end
class Skill < ActiveRecord::Base
belongs_to :section
has_one :level, through: :section
has_one :checklist, through: :level
has_one :organization, through: :checklist
has_many :assessments
end
class Assessment < ActiveRecord::Base
belongs_to :skill
has_one :section, through: :skill
has_one :level, through: :section
has_one :checklist, through: :level
has_one :checklist_owner, through: :checklist, source: :organization
belongs_to :organization
end
Using the above, I can get an assessment's organization:
Assessment.last.organization # yields organization 1
I can also get an assessment's checklist_owner:
Assessment.last.checklist_owner # yields organization 2
But when I try to use checklist_owner in a where, the association seems to forget to use the :through. For example, if I run:
Assessment.where(organization: Organization.find(2), checklist_owner: Organization.find(1))
... this translates to SQL:
SELECT "assessments".* FROM "assessments" WHERE "assessments"."organization_id" = 2 AND "assessments"."organization_id" = 1
See how the SQL has two "assessments"."organization_id" = statements? Why does it do that?
Have you tried using joins?
something like:
Assessment.joins(skill: { section: { level: :checklist } }).where(organization: Organization.find(2), checklists: { organization_id: Organization.find(1) })
I know it look bad, but it seems that your relation from assessment to checklist is very complicated. This would take care of any weird relations being made.
I have four models
class Company < ActiveRecord::Base
has_many :share_types
belongs_to :user
end
class ShareType < ActiveRecord::Base
has_many :shares
belongs_to :company
end
class Share < ActiveRecord::Base
belongs_to :user
belongs_to :share_type
end
class User < ActiveRecord:Base
has_many :companies
has_many :shares
end
Now list of all companies where company is owned by current_user or user have shares in a company something like this.
Company.joins(share_types:[:shares]).where("shares.user_id=? OR companies.user_id=?", #user.id, #user.id)
but with left outer join another I do not know how to use includes with or conditions another hint is
Company.includes(share_types:[:shares]).where(shares:{user_id: #user.id} OR companies:{user_id: 1})
How can I do that.
I am able to get my expected result with the help of references. Here is my query just posting to help others.
Company.includes(share_types:[:shares]).where("shares.user_id=? OR companies.user_id=?", 1,1).references(:shares)
its working thanks to The Rails 4 Way by Obie Fernandez
I am trying to establish a direct relation via has_one between two models, Client and Address as in has_one :billing_address but Client doesn't have a direct relation to Address, Contact does, the models:
Client
class Client < ActiveRecord::Base
belongs_to :contact
accepts_nested_attributes_for :contact
end
Contact
class Contact < ActiveRecord::Base
has_one :client
has_many :addresses, dependent: :destroy
accepts_nested_attributes_for :addresses, allow_destroy: true
end
Address
class Address < ActiveRecord::Base
belongs_to :contact
enum kind: [:address, :shipping, :billing]
end
So what I want is to to be able to do Client.shipping_address or Client.billing_address, the enum in the Address model is what will allow the query. The reason behind that is because the Contact of Client will have two address records, one for billing and one for shipping and I want quick access via relations
I tried in the Client model:
has_one(:billing_address, -> { where(kind: :billing) }, class_name: Address, through: :contact)
But when in the view I o:
client.billing_address
I get a undefined method to_sym' for nil:NilClass And I can't seem to resolve it, thanks.
You need to specify the :source on the association since it cannot be inferred.
has_one :billing_address, through :contact, source: :addresses, -> { where(kind: :billing) }
Without :source, it's going to look for a :billing_address association on the Contact model.
Source
Update
After reading up on the enum docs, it looks like you may need to modify the scope, referencing the mapping directly:
-> { where(kind: Address.kinds[:billing]) }
I believe this is because the :kind field in the database is expected to be type INTEGER.
I'm trying to make a has_many relation work for object to be created.
It is a simple case and despite many efforts and researches through the web, I cannot find why my code is not working.
I have the following classes (note: some variables use French names):
class Comptes::Category < ActiveRecord::Base
has_many :categorizations, dependent: :destroy
accepts_nested_attributes_for :categorizations
has_many :transactions, through: :categorizations
validates :nom, presence: true, uniqueness: true
end
class Comptes::Transaction < ActiveRecord::Base
has_many :categorizations, dependent: :destroy
accepts_nested_attributes_for :categorizations
has_many :categories, through: :categorizations
... # some validations
end
class Comptes::Categorization < ActiveRecord::Base
belongs_to :transaction
belongs_to :category
validates :transaction, presence: true
validates :category, presence: true
end
Category and Transaction are the basic models and Categorization is dedicated to the association (this is a basic account - transaction system).
What I can do is create a transaction and a category then fill transaction.categories with the category (transaction has thus an id).
What I cannot do is:
transaction = Comptes::Transaction.new ...
category = Comptes::Category.first
transaction.categories << category
# OR
transaction.categorizations.build category: category
# OR
# use categorizations_attributes in and accepts_nested_attributes_for.
Thank you very much for any help
Edit: this is done in rails 4.0.0
And I found that the issue was coming from the validation in Comptes::Categorization.
This prevents creation of new categorizations if the transaction or category does not exist yet.
Update (18/08/2014): the issue is coming from the validation in Categorizations, which prevent from creating the association without existing transaction and category. This may be an issue in rails 4.0.0. To see...
Transaction class is not under the module Comptes. Therefore, when you do has_many :categorizations or has_many :categories in it, the corresponding models are inferred as Categorization and Category instead of Comptes::Categorization and Comptes::Category.
To resolve this, you need to specify the class_name option of the association because the name of the model can't be inferred from the association name.
Update the class Transaction as below:
class Transaction < ActiveRecord::Base
has_many :categorizations, class_name: "Comptes::Categorization" , dependent: :destroy
accepts_nested_attributes_for :categorizations
has_many :categories, through: :categorizations, class_name: "Comptes::Category"
end
I have two models for Show and Performance (show as in a play or comedy show). They are associated like this in the models:
class Show < ActiveRecord::Base
has_many :performances, :dependent => :destroy
accepts_nested_attributes_for :performances
end
class Performance < ActiveRecord::Base
belongs_to :show
end
In the Performance model there is a datetime called :start_time.
How do I define a scope in the model which returns all Shows with at least one performance whose :start_time is in the future?
Also, how do I define a scope that returns all Shows that do not have any performances in whose :start_time is in the future?
class Show < ActiveRecord::Base
has_many :performances, :dependent => :destroy
accepts_nested_attributes_for :performances
scope :shows_with_pending_performance, includes(:performances).where("performances.start_time >= ? ", Date.today)
end
class Performance < ActiveRecord::Base
belongs_to :show
end