This is probably a newbie question, but I can't seem to think of a good solution. I have a company table that has_many users through groups that can also be administrators of the company (enabling them to edit the company but only one company per user).
What's the best way to set this up in Rails?
I can't add an admin field to the user table, because it wouldn't discriminate which company he/she is administrating. But if I do a company_id field, what would that relationship look like in Rails (since it's a sort of somtimes_has_one relationship!). I could leave it without a relationship, but that doesn't seem proper...
Thanks in advance for any help!
From what I understand, you have a user which might belong to a company, and if it does, it might actually administer it.
You could setup Group to have for example, company_id, user_id and an admin field (this way you get to know which users belong to which company, and if they also administrate that company)
For a user to belong to just one company you could add a validation for uniqueness per two columns (company_id and user_id)
You could get one company's administrators by doing
class Company < ActiveRecord::Base
has_many :groups
has_many :users, through: :groups
has_many :administrators, through: :groups, source: :user, conditions: ["groups.admin = ?", true]
end
and call company.administrators or company.users for all users
You could also do something like
class User < ActiveRecord::Base
has_one :group
has_one :company, through: :group
has_one :administered_company, through: :group, source: :company, conditions: ["groups.admin = ?", true]
end
so you can call user.company or user.administered_company
and so on...
Related
I'm setting up an app that has Users and Brands. Most users will not be associated with a brand, and will only be able to comment on Brand pages. Some users, however, will be associated with a single brand. I want these users to be the "admins" or owners of this brand. E.g. Users A and B are both "admins" of a brand, and so can create/edit/update the brand, etc. My question is, how should I set up the Brand resource such that it "belongs_to" multiple users? I understand that I could say brands have_many users, but is it weird to say that an object "has" a user? Is it more appropriate to "belong" to users? This description leads me to believe so: "For example, it makes more sense to say that a supplier owns an account than that an account owns a supplier."
It's definitely a has_many relationship.
But it may be clearer to refer to those special users as 'administrators' or 'admins'
class Brand
has_many :administrators, class_name: 'User'
end
If it turns out that a user can be administrator for several brands, then you'll need a join table, either HABTM or HMT. HMT is the better choice in case you want to store characteristics about the join (e.g. when he became administrator)
class BrandUser
belongs_to :user
belongs_to :brand
end
class Brand
has_many :brand_users
has_many :administrators, through: :brand_users, source: :user
end
class User
has_many :brand_users
has_many :brands, through: :brand_users
end
I am currently trying to create a system which allows for specific users to create a Course record which can be enrolled in by many other users. I've tried a few association techniques such as has_and_belong_to_many, has_many :through and number of other setups but have been unable to get it right.
Basically all that I need is the following:
Course belongs to (is created by) a single User (foreign_id => admin_id)
Course has many enrolled Users (Join Table?)
User has many created Courses
User can belong to many Courses
If you have any idea how this would be accomplished I would greatly appreciate your input.
I would use a Course model to represent the course information, with a user_id attribute to associate with the user who created the course. I would also make an association table/model called Enrollment which is an association between a User and a Course. You can then do something like this:
#User.rb
has_many :courses
has_many :enrollments
has_many :enrolled_courses, through: :enrollments, source: :course
#Enrollment.rb
belongs_to :course
belongs_to :user
#Course.rb
belongs_to :user
has_many :enrollments
has_many :users, through: :enrollment
With this configuration you can call course.user to receive the user who created the course, but you could also call course.users to receive the users who are enrolled in the course. On the opposite side, you can call user.enrolled_courses to receive the list of courses a user is enrolled in, or user.courses to receive a list of courses a user has created.
I have the following setup in my database. We have users. Each user has many entries. Users also belong to organizations, through a table called organization_users.
class User < ActiveRecord::Base
has_many :entries
has_many :organization_users
has_many :organizations, :through => :organization_users
end
class Entry < ActiveRecord::Base
belongs_to :user
end
class Organization < ActiveRecord::Base
has_many :organization_users
has_many :users, :through => :organization_users
end
class OrganizationUser < ActiveRecord::Base
belongs_to :user
belongs_to :organization
end
Here's my question: for a given organization, I want to get a list of all the entries for the users in that organization. Is there a nice compact way to accomplish this? I know I can iterate over all users in the organization and get the entries, but I'm not sure if there is a nice rails-y way to do this.
You can do the following assuming you have a foreign key called organization_id in organization_users table as per your Model
Entry.joins(:user => :organization_users).where("organization_users.organization_id = ?", org_id)
Where org_id is the id of the given organization. This will give you all entries of all users in an organization
Try something like that :
my_org = Organization.find(id)
my_org.users.eager_load(:entries)
First you get the organization you want to query. Then via :through association you can directly retrieve all the users for that organization. And last using eager_load, in one query you get all the entries. The result will be an ActiveRecord::Relation.
I'd like to give my users the ability to specify which Organization is their default Organization. Each user can belong to multiple Organizations, as shown below:
Class User
has_many :memberships, dependent: :destroy
has_many :organizations, through: :memberships, source: :organization
end
Class Organization
has_many :memberships, dependent: :destroy
has_many :users, through: :memberships, source: :user
end
Class Membership
belongs_to :user
belongs_to :organization
end
What would be the most appropriate way to specify that an organization and/or membership is the users default? This way, I can display the default organizations feed when they log into the application.
I've tried adding a default boolean attribute to memberships, which seems to work but just doesn't feel right. I've considered adding a default_organization attribute to the User model, which would just hold the ID of the organization, but again that doesn't seem right.
Is there a Rails approved way of handling this?
Thinking about it there are several ways you can approach this:
since this is a many to many association you can add a a field on the association model, but that needs some validation to work correctly since you can by mistake set more than one of those relations to true.
the other way is by setting a field to your user model like you described, its a little clunky but it would work.
the last way I can think, and I think is the best one is make a has_one relationship between the user and an organization. something like this:
has_one :organization, as: :default_organization
Hope it helped
I have been doing some searching around Google and this site for some ways to go about constructing some models for an application I am working on.
I plan to have Users and Teams. A user can join a team and one team only. A team can obviously have many users. Also, I want to add a 'leader' role inside the team that is assigned to the User who creates a Team but can later be passed on to another User who is already a part of that team.
I have seen some examples of models for something like this and saw a few like this:
class User < ActiveRecord::Base
has_one :team
has_many :memberships
end
class Membership < ActiveRecord::Base
belongs_to :user
belongs_to :team
end
class Team < ActiveRecord::Base
has_many :memberships
has_many :users, :through => :memberships
end
Why is the Membership model necessary? I have seen it in a few examples and I am not sure I quite follow the logic of why it is in there and what it is doing.
Also, if I did something like has_one :leader in the Team model and had the Leader model, would that be considered the best practice for determining a leader in a Team? It seems like a bit much to have an entire model/table for Leader.
The Memberships model is allowing for a many-to-many relationship there. It's acting as the join table. It would allow Users to belong to many Teams and Teams to have many Users.
Sounds like you just want a one-to-many though?
class User < ActiveRecord::Base
belongs_to :team
end
class Team < ActiveRecord::Base
has_many :users
end
I'll have to double check this part but you can use additional parameters to specify the models in your assocation if they don't match up with the name you need. So Team could have a leader that's just a User model.
class Team < ActiveRecord::Base
has_many :users
has_one :leader, :class_name => "User", :foreign_key => "user_id"
end
the rails guides page on associations has a good summary including the part about the :class_name and other options
http://guides.rubyonrails.org/association_basics.html#the-has_many-association