Ruby on Rails - primary and foreign key
I am creating a site in Ruby on Rails, I have two models: model User
and model Transaction
.
These models are account specific, so they have a field called account_id
I am trying to communicate between them like this:
class User < ActiveRecord::Base
belongs_to :account
has_many :transactions
end
class Transaction < ActiveRecord::Base
belongs_to :account
belongs_to :user
end
I use the following associations:
user = User.find(1)
transactions = user.transactions
The application is currently trying to find transactions from user_id
, here is the SQL it generates:
Mysql::Error: Unknown column 'transactions.user_id' in 'where clause': SELECT * FROM `transactions` WHERE (`transactions`.user_id = 1)
This is not correct, since I would like to find transactions through account_id
, I tried setting associations like this:
class User < ActiveRecord::Base
belongs_to :account
has_many :transactions, :primary_key => :account_id, :class_name => "Transaction"
end
class Transaction < ActiveRecord::Base
belongs_to :account
belongs_to :user, :foreign_key => :account_id, :class_name => "User"
end
This almost achieves what I'm looking for and generates the following SQL:
Mysql::Error: Unknown column 'transactions.user_id' in 'where clause': SELECT * FROM `transactions` WHERE (`transactions`.user_id = 104)
The number 104
is correct account_id
, but it is still trying to query the transaction table for the field user_id
. Can anyone give me some advice on how to set up associations to query the transaction table for account_id
instead user_id
, resulting in an SQL query:
SELECT * FROM `transactions` WHERE (`transactions`.account_id = 104)
Greetings
Eef
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class Account < ActiveRecord::Base
has_many :users
has_many :transactions
end
class User < ActiveRecord::Base
has_many :transactions, :through => :account
end
http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html#M001833
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If transactions
there is no column in the table user_id
, then you should use the model Account
to select all transactions:
class User < ActiveRecord::Base
belongs_to :account
end
class Account < ActiveRecord::Base
has_many :transactions
has_one :user # or has_many :users
end
class Transaction < ActiveRecord::Base
belongs_to :account
end
User.find(1).account.transactions
Note that you need to remove has_many :transactions
from User
and belongs_to :user
from Transaction
as they assume you have a column user_id
.
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I want to store data in an address model that is related to the student model
class AddressesController < ApplicationController
def new
@address = Address.new
end
def create
@address = Address.create(:address_date => Time.now,
:student_id => @student.id)
end
private
def address_params
params.require(:address).permit(:gali_no, :house_no_flate_no, :vill_town_city, :district, :state, :post_code, :country)
end
end
class StudentsController < ApplicationController
def show
end
def new
@student = Student.new
end
def create
@student = Student.new(student_params)
if @student.save
redirect_to root_url, :notice => "You have been registered"
else
render "new"
end
end
private
def student_params
params.require(:student).permit(:f_name, :l_name, :email, :password, :password_confirmation, :mobile_no)
end
end
class Student < ActiveRecord::Base
has_many :addressess, :dependent => :destroy
attr_accessor :password
before_save :encrypt_password
validates_confirmation_of :password
validates_presence_of :f_name
validates_presence_of :l_name
validates_presence_of :password, :on => :create
validates_presence_of :email
validates_uniqueness_of :email
def encrypt_password
if password.present?
self.password_salt = BCrypt::Engine.generate_salt
self.password_hash = BCrypt::Engine.hash_secret(password, password_salt)
end
end
end
class Address < ActiveRecord::Base
belongs_to :student
end
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