Help with Model Associations

Rails
1

HI everybody,

I need some help with model association.

Here I have one user table.

User table.
id name
1 XXX
2 YYY
3 ZZZ
4 XYZ

Message Table

id sender_id receiver_id message
1 1 2 HI. HOW R U
2 2 1 YEAH. FINE
3 2 4 HI. WR R U NOW?

  1. Here I want get the sender_name and receiver name for an message.
    Like below
    @msg=Message.find(1)
    @msg.sender.name
    @msg.receiver.name

  2. Same like I want to get the sent and received messages for a
    Particular message.
    @user=User.find(1)
    @user.sent_msg
    @user.received_msg

Can any one help how I have to build the association between these two
models, Here I dont want to create one more table.

Regards,
T.Veeraa.

2

On Dec 12, 2007 8:20 PM, Veera S.
[email protected] wrote:

id name
3 2 4 HI. WR R U NOW?

  1. Here I want get the sender_name and receiver name for an message.
    Like below
    @msg=Message.find(1)
    @msg.sender.name
    @msg.receiver.name

class Message < ActiveRecord::Base
belongs_to :sender, :class_name => “User”
belongs_to :receiver, :class_name => “User”
end

  1. Same like I want to get the sent and received messages for a
    Particular message.
    @user=User.find(1)
    @user.sent_msg
    @user.received_msg

class User < ActiveRecord::Base
has_many :sent_messages, :class_name => “Message”, :foreign_key =>
“sender_id”
has_many :received_messages, :class_name => “Message”, :foreign_key
=> “receiver_id”
end

Pat

3

Pat M. wrote:

On Dec 12, 2007 8:20 PM, Veera S.
[email protected] wrote:

id name
3 2 4 HI. WR R U NOW?

  1. Here I want get the sender_name and receiver name for an message.
    Like below
    @msg=Message.find(1)
    @msg.sender.name
    @msg.receiver.name

class Message < ActiveRecord::Base
belongs_to :sender, :class_name => “User”
belongs_to :receiver, :class_name => “User”
end

  1. Same like I want to get the sent and received messages for a
    Particular message.
    @user=User.find(1)
    @user.sent_msg
    @user.received_msg

class User < ActiveRecord::Base
has_many :sent_messages, :class_name => “Message”, :foreign_key =>
“sender_id”
has_many :received_messages, :class_name => “Message”, :foreign_key
=> “receiver_id”
end

Pat

@user=User.find(1)
@user.sent_messages working.

But
@msg = Message.find(1)
@msg.sender returns nil

4

sorry for the mistake

class Message < ActiveRecord::Base
belongs_to :sender, :class_name => “User”, :foreign_key=>“sender_id”
belongs_to :receiver, :class_name => “User”,
:foreign_key=>“receiver_id”
end

Veera S. wrote:

class Message < ActiveRecord::Base
belongs_to :sender, :class_name => “User”, :foreign_key=>“id”
belongs_to :receiver, :class_name => “User”, :foreign_key=>“id”
end

class User < ActiveRecord::Base
has_many :sent_messages, :class_name => “Message”, :foreign_key =>
“sender_id”
has_many :received_messages, :class_name => “Message”, :foreign_key
=> “receiver_id”
end

Working fine.

Now I can query from both the ends.

Thanks for your help Pat M…

Regards,
Veeraa.T

5

class Message < ActiveRecord::Base
belongs_to :sender, :class_name => “User”, :foreign_key=>“id”
belongs_to :receiver, :class_name => “User”, :foreign_key=>“id”
end

class User < ActiveRecord::Base
has_many :sent_messages, :class_name => “Message”, :foreign_key =>
“sender_id”
has_many :received_messages, :class_name => “Message”, :foreign_key
=> “receiver_id”
end

Working fine.

Now I can query from both the ends.

Thanks for your help Pat M…

Regards,
Veeraa.T