Question

I’m new to this. I have a (sqlite3, but with ActiveRecord it doesn’t matter) table called Messages and a model called Message. I want to find all messages in database that have user_id or reciever_id equal to the object user and his attribute id (for short user.id). I know it’s probably just one simple line of code, but I wanna do it the right “rails” way and I don’t have much experience with this.

I’m using Rails 3. Thanks for any help.

Cheers

Answer 1

I suspect that what you will want this relationship in many places in your code, and actually this represents a fundamental part of your application’s design.

Conceptually a ‘message’ belongs to a ‘sender’ and also to a ‘receiver’. In reverse, a ‘user’ has many messages that she has sent, and many messages that she has received.

in the Message model, add the following

belongs_to :user
belongs_to :receiver, :class_name => "User"

in the User model, add the following

has_many :messages
has_many :sent_or_received_messages, :class_name => "Message", :conditions => ["user_id = ? OR receiver_id = ?", id, id])

Now you can do this:

my_user.messages # all of the messages the user has sent
my_message.user # the user who sent the message
my_message.receiver # the user who received the message
my_user.sent_or_received_messages # all messages where the user was a sender or a receiver