users dialogs database scheme

I want to create users dialog

How I must do?

Create one record with sender_id and recipient_id and then "select * from table_dialog where sender_id=current.id or recipient_id =current.id" also add 2 columns deleted_by_sender and deleted_by_recipient

Or create 2 record in开发者_运维百科 database for each dialog

What is the best solution? Or propose your own solution please

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If by "dialog" you mean a "conversation between TWO participants", then it is very similar to classic mailbox. The following code extract(with abbreviation) from one of my project which implements similar functionality. Maybe will be helpful.

class User < ActiveRecord::Base
  # ....
  has_many :received_messages, :class_name => "Message", :foreign_key => 'recipient_id'
  has_many :sent_messages, :class_name => "Message", :foreign_key => 'sender_id'
  # ....
end

class Message < ActiveRecord::Base
  validates :content, :presence => true
  validates :sender, :presence => true, :associated => true
  validates :recipient, :presence => true, :associated => true

  belongs_to :sender, :class_name => 'User', :foreign_key => 'sender_id'
  belongs_to :recipient, :class_name => 'User', :foreign_key => 'recipient_id'

  default_scope order('created_at desc')

  # usage: user.received_messages.unread
  scope :unread, where('unread = true')

  def self.chat_between(first_user, second_user)
    where('(recipient_id = ? AND sender_id = ?) OR (recipient_id = ? AND sender_id = ?)',
            first_user.id, second_user.id, second_user.id, first_user.id)
  end

  def self.read_all!
    self.update_all('unread = false')
  end

  def read!
    self.update_attribute :unread, false
  end

  def new?(user)
    (recipient == user) && (unread == true)
  end

end