Has_many with different foreign key


I am new to rails and am trying to get my associations straight. I
have a User model and a Property model. I’d like to track who has
updated a property record, so I added an integer field to the
properties table called updated_by. Then I made the following

In the User model:
has_many :properties

In the Property model:
belongs_to :user, :class_name => “User”, :foreign_key =>

Here’s what I see inside of the rails console:

prop = Property.first
=> #<Property id: 1, name: “Main Street Center”, …, updated_by: nil>

usr = User.first
=> #<User id: 1, login: “sshartles”, name: “Sam Shartles”, … >

prop.user = usr
=> #<User id: 1, login: “sshartles”, name: “Sam Shartles”, … >

=> 1

NoMethodError: undefined method `name’ for 1:Fixnum
from (irb):5

I’m not sure what I’ve done, but I think it’s something simple. Any
help would be massively appreciated.