1

我写了我的rails（3.2.3）应用程序......

配置/应用程序.rb：

# ...

class MyWebApp
  class Application < Rails::Application

    # ...

    config.before_initialize do
      $my_config = MyConfig.new
    end
  end
end

配置/数据库.yml：

development:
  adapter: mysql2
  encoding: utf8
  reconnect: true
  database: <%=$my_config.config['db']['basename']%>_development
  pool: 5
  username: <%=$my_config.config['db']['username']%>
  password:
  socket: /var/run/mysqld/mysqld.sock

然后， rake db:create 引发：

rake aborted!
undefined method `config' for nil:NilClass
(erb):15:in `<main>'
/home/sn/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/erb.rb:838:in `eval'
/home/sn/.rbenv/versions/1.9.3-p194/lib/ruby/1.9.1/erb.rb:838:in `result'
/home/sn/dev/mywebapp/vendor/bundle/ruby/1.9.1/gems/railties-3.2.3/lib/rails/application/configuration.rb:115:in `database_configuration'
...

在我手动创建数据库后， rake db:migrate 成功。所以我阅读了 databases.rake 并发现 db:migrate 调用 :environment task 但 db:create 没有。

activerecord-3.2.3/lib/active_record/railties/databases.rake：

task :create => :load_config do
  configs_for_environment.each { |config| create_database(config) }
  ActiveRecord::Base.establish_connection(configs_for_environment.first)
end

task :migrate => [:environment, :load_config] do
  ActiveRecord::Migration.verbose = ENV["VERBOSE"] ? ENV["VERBOSE"] == "true" : true
  ActiveRecord::Migrator.migrate(ActiveRecord::Migrator.migrations_paths, ENV["VERSION"] ? ENV["VERSION"].to_i : nil) do |migration|
    ENV["SCOPE"].blank? || (ENV["SCOPE"] == migration.scope)
  end
end

您知道在 rake db:create 上正确初始化 $my_config 变量的任何简单方法吗？

4

1 回答 1

0

您可以向任务添加依赖项，尝试将此行放在 Rakefile 的末尾：

namespace :db do 
  task :create => [:environment, :load_config]
end
于 2012-06-07T11:04:41.940 回答