Write a migration with reference to a model twice

Question

I have a message model (Message) and this models as a userTo and userFrom, so two references to User. How can i write the migration? My user model is User.

Thank you

Answer 1

In the migration, create two different columns for each kind of user. For example:

add_column :messages, :sender_id, :integer
add_column :messages, :receiver_id, :integer

Then in the model, that's where the logic to map each column to the User class happens:

belongs_to :sender, :class_name => 'User'
belongs_to :receiver, :class_name => 'User'

Of course, use your own words for sender and receiver, but Rails will automatically associate sender to the sender_id column (and the same logic for receiver)

You will then be able to interact with both user user.sender and user.receiver.