铁轨4耙子中止了！ 在heroku上

Question

rake db：migrate在开发中运行良好，app也是如此。 只有heroku我才遇到麻烦

$ heroku run rake db:migrate

Running `rake db:migrate` attached to terminal... up, run.5905
-- create_table(:users)
-- create_table(:users)
rake aborted!
ActiveRecord::MigrationProxy#disable_ddl_transaction delegated to 
migration.disable_ddl_transaction, but migration is nil: 
#<struct ActiveRecord::MigrationProxy name="DeviseCreateAdmins", 
version=20130802210826, filename="/app/db/migrate/20130802210826_devise_create_admins.rb", 
scope=""

迁移文件：

class DeviseCreateAdmins < ActiveRecord::Migration
  create_table :users do |t|
    t.database_authenticatable
    t.confirmable
    t.recoverable
    t.rememberable
    t.trackable
    t.timestamps
  end
end

有没有人对迁移失败的原因有任何想法？

Answer 1

你错过了一个方法名，

class DeviseCreateAdmins < ActiveRecord::Migration
  def change
    create_table :users do |t|
      t.database_authenticatable
      t.confirmable
      t.recoverable
      t.rememberable
      t.trackable
      t.timestamps
    end
  end
end

注意开始时的def change 。