has_many with different foreign key

rubyonrails-talk
1

Hello,

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 changes:

In the User model:   has_many :properties

In the Property model:   belongs_to :user, :class_name => "User", :foreign_key => 'updated_by'

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", ... >

prop.updated_by

=> 1

prop.updated_by.name

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.

Sam

2

s. shartles wrote:

In the User model:   has_many :properties

In the Property model:   belongs_to :user, :class_name => "User", :foreign_key => 'updated_by'

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", ... >

prop.updated_by

=> 1

prop.updated_by.name

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

Yeah the fixnum error is because updated_by is just an integer field to rails.

If you tried: prop.user = usr prop.user.name #=> "Sam Shartles"

This should get you are trying to acheive:

In the User model:   has_many :properties, :foreign_key => 'updated_by'

In the Property model:   belongs_to :updated_by, :class_name => 'User', :foreign_key => 'updated_by'

I must admit in the past I've tended to use 'updated_by_id' instead as your field name that way you can access both updated_by_id (returns int) and updated_by (returns user).

You may also look at the userstamp plugin:

Cheers Luke