Dealing with has_one and has_many associations with one user model-CodePudding

I currently have a User model

class User < ApplicationRecord
  has_one :leases
end

a Lease model

class Lease < ApplicationRecord  
  belongs_to :tenant, class_name: 'User'
  belongs_to :landlord, class_name: 'User'
end

and a Rental model

class Rental < ApplicationRecord
  has_one :lease, dependent: :destroy
end

and I only have one user model supporting tenants and landlords.

The problem I'm facing is that a landlord can have multiple leases with many different tenants, but tenants can only have one lease at a time.

I'm somewhat confused on how I should structure this properly. Should I have a has_many relation with the User model and the Lease model instead of the has_one and then just a method say lease on the User model to get the lease for a tenant? What I would like to have is something like

tenant.lease

and

landlord.leases

Could I just do?

class User < ApplicationRecord
  has_one :lease, foreign_key: "tenant_id"
  has_many :leases, foreign_key: "landlord_id"
end

this seems to work, but I'm not sure if its the right way to go.

CodePudding user response：

Using STI, you could have the following models

==> user.rb <==
class User < ApplicationRecord
end

==> landlord.rb <==
class Landlord < User
  has_many :leases
end

==> tenant.rb <==
class Tenant < User
  has_one :lease
end

==> lease.rb <==
class Lease < ApplicationRecord
  belongs_to :tenant
  belongs_to :landlord
end

Then you can do things like

irb(main):003:0> landlord = Landlord.create(name: 'the landlord')
=> #<Landlord id: 5, name: "the landlord", type: "Landlord", created_at: "2022-01-03 22:16:56", updated_at: "2022-01-03 22:16:56">

irb(main):004:0> tenant = Tenant.create(name: 'the tenant')
=> #<Tenant id: 6, name: "the tenant", type: "Tenant", created_at: "2022-01-03 22:17:09", updated_at: "2022-01-03 22:17:09">

irb(main):005:0> lease = Lease.create(tenant: tenant, landlord: landlord)
=> #<Lease id: 3, tenant_id: 6, landlord_id: 5, created_at: "2022-01-03 22:17:28", updated_at: "2022-01-03 22:17:28">

irb(main):006:0> tenant.lease
=> #<Lease id: 3, tenant_id: 6, landlord_id: 5, created_at: "2022-01-03 22:17:28", updated_at: "2022-01-03 22:17:28">

irb(main):007:0> landlord.leases
=> #<ActiveRecord::Associations::CollectionProxy [#<Lease id: 3, tenant_id: 6, landlord_id: 5, created_at: "2022-01-03 22:17:28", updated_at: "2022-01-03 22:17:28">]>

To accomplish this, you only need to add a type column to your User model and Rails will take care of the rest.

CodePudding user response：

In my opinion, you should go with has_many approach. As landlord and tenant both are users. in place of using tenant_id and landlord_id, you have to use 'user_id' and to identify user, use user_type i.e. tenant and lanlord.

Just an opinion !!