Devise migration on existing model

Question

I'm migrating from Authlogic to Devise.

UPDATED:

The migration of devise tries to re-create the table users, so i changed as you can see below the create_table to change_table and drop table at the end to remove what i add

The problem is when I run rake i get an error .

This is the error I get when running rake.

==  DeviseCreateUsers: migrating ==============================================
-- change_table(:users)
rake aborted!
An error has occurred, this and all later migrations canceled:

SQLite3::SQLException: duplicate column name: email: ALTER TABLE "users" ADD "email" varchar(255) DEFAULT '' NOT NULL

This is the migration

class DeviseCreateUsers < ActiveRecord::Migration
  def self.up
    change_table(:users) do |t|
      t.database_authenticatable :null => false
      t.recoverable
      t.rememberable
      t.trackable

      # t.confirmable
      # t.lockable :lock_strategy => :failed_attempts, :unlock_strategy => :both
      # t.token_authenticatable


      t.timestamps
    end

    add_index :users, :email,                :unique => true
    add_index :users, :reset_password_token, :unique => true
    # add_index :users, :confirmation_token,   :unique => true
    # add_index :users, :unlock_token,         :unique => true
  end

  def self.down
    remove_column :users, :database_authenticatable
    remove_column :users, :recoverable
    remove_column :users, :rememberable
    remove_column :users, :trackable
    remove_index :users, :email
    remove_index :users, :reset_password_token
  end
end

In my schema.rb i already have this from Authlogic.

  create_table "users", :force => true do |t|
    t.string    "username"
    t.string    "email"
    t.string    "crypted_password"
    t.string    "password_salt"
    t.string    "persistence_token"

I think it sees some kind of conflict that i'm not able to realize how to avoid with those devise helpers

Thank you!

Answer 1

The error that you're getting is because you are trying to recreate the email field which you already have. The email field is created in the devise helper t.database_authenticatable. You can use your old user table with the new system, but you don't need to include t.database_authenticatable, you just need to rename your old field names. Looking in the Documentation for Devise, you can see that database_authenticatable just creates three fields: email, encrypted_password and password_salt. They are the same as the email, crypted_password, and password_salt that you already have in your authlogic user table, so you can use change_table like so:

def self.up
  change_table(:users) do |t|
    t.recoverable
    t.trackable
    # rememberable uses remember_token, but this field is different
    t.rename :remember_token_expires_at, :remember_created_at
    # these fields are named differently in devise
    t.rename :crypted_password, :encrypted_password
  end
end

Answer 2

Instead of changing the create_table to change_table, you can just add the following line just before create_table:

rename_table :users, :old_users_authlogic

Then, right after the create_table:

say_with_time 'Migrating users from Authlogic to Devise...' do
  execute "INSERT INTO users (id, email, ...) SELECT id, email FROM old_users_authlogic"
end

If you are using indexes with referential integrity, don't forget to update them to the new table, as the rename_table will make them point to old_users_authlogic.