Modify Devise to support UUID primary key - postgresql

Question

I want to modify Devise to make it work with a users table with a UUID primary key with PostgreSQL.
Here is the migration:
class DeviseCreateUsers < ActiveRecord::Migration
def change
create_table :users, id: false do |t|
t.uuid :uuid, null: false
# ...
end
change_table :users do |t|
t.index :uuid, unique: true
# ...
end
end
def migrate(direction)
super
if direction == :up
# This is only necessary because the following does not work:
# t.uuid :uuid, primary: true, null: false
execute "ALTER TABLE users ADD PRIMARY KEY (uuid);"
end
end
end
Here is the User model:
class User < ActiveRecord::Base
primary_key = :uuid
devise :database_authenticatable, :recoverable, :registerable,
:rememberable, :trackable, :validatable
validates :uuid, presence: true
before_validation :ensure_uuid
def ensure_uuid; self.uuid ||= SecureRandom.uuid end
end
Here is the error:
PG::Error: ERROR: operator does not exist: uuid = integer
LINE 1: ...ECT "users".* FROM "users" WHERE "users"."uuid" = 1 ORDER...
^
HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts.
: SELECT "users".* FROM "users" WHERE "users"."uuid" = 1 ORDER BY "users"."uuid" ASC LIMIT 1
Extracted source (around line #5):
1 .navbar-inner
2 .container
3 = a_nav_tag "App", root_path
4 - if user_signed_in?
5 %ul.nav.pull-right
6 %li.dropdown#user_menu
7 %a.dropdown-toggle(data-toggle="dropdown" href="#")
As you can see above, user_signed_in? is broken. I expect there are several changes needed to move from a 'normal' auto-incrementing ID to a UUID.
For now, I'm just posting the question. I'll take a swing at this later today. If you happen to know how to do this -- or know of a Devise fork, I'd appreciate it.

Answer 1

I've done this in Rails 4 simply by making the id column a uuid data type when creating the table, and no other configuration changes whatsoever. ie. do not create a column named 'uuid', just change the type of the 'id' column to uuid.

Answer 2

Just clear your browser's cookie for the web app (in my case, localhost). The error above is caused because the session was retaining the old user primary key, 1.
After that, things work in my testing. I hope this isn't just luck, it would be a good design if Devise was agnostic about the primary key. (In Devise's code, I saw no use of .id except in some tests.)

Answer 3

2020 answer:
when creating the users table, set the ID as uuid
def change
enable_extension 'pgcrypto' # needed if not already enabled
create_table :users, id: :uuid do |t|
t.string :email,
...