Rails 可安装引擎：在迁移中插入数据行

Question

Inside Rails 可安装引擎我生成了一个模型：

rails g model Sources domain:string source_alias:string is_social:boolean is_organic:boolean organic_query_param:string

这里是迁移文件 (20131220160128_create_sourcebuster_sources.rb)

class CreateSourcebusterSources < ActiveRecord::Migration
  def change
    create_table :sourcebuster_sources do |t|
      t.string :domain, null: false
      t.string :source_alias
      t.boolean :is_social, default: false
      t.boolean :is_organic, default: false
      t.string :organic_query_param

      t.timestamps
    end
    add_index :sourcebuster_sources, :domain, unique: true
    add_index :sourcebuster_sources, :is_social
    add_index :sourcebuster_sources, :is_organic

    Sourcebuster::Source.create domain: "yahoo.com",
                                source_alias: "yahoo.com",
                                is_social: false,
                                is_organic: true,
                                organic_query_param: "p"
  end
end

将其复制到虚拟应用程序：

rake sourcebuster:install:migrations

迁移文件名称不同——20131220164445_create_sourcebuster_sources.sourcebuster.rb——但内容与上述相同。

好的，bundle exec rake db:migrate

当我尝试插入数据行时，它给了我一个错误：

==  CreateSourcebusterSources: migrating ======================================
-- create_table(:sourcebuster_sources)
-> 0.0364s
-- add_index(:sourcebuster_sources, :domain, {:unique=>true})
-> 0.0066s
-- add_index(:sourcebuster_sources, :is_social)
   -> 0.0069s
-- add_index(:sourcebuster_sources, :is_organic)
   -> 0.0046s
rake aborted!
An error has occurred, this and all later migrations canceled:

uninitialized constant Sourcebuster::Source/Users/Alex/Ruby/sourcebuster/test/dummy/db/migrate/20131220164445_create_sourcebuster_sources.sourcebuster.rb:17:in `change'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/migration.rb:571:in `exec_migration'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/migration.rb:555:in `block (2 levels) in migrate'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/migration.rb:554:in `block in migrate'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/connection_adapters/abstract/connection_pool.rb:294:in `with_connection'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/migration.rb:553:in `migrate'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/migration.rb:709:in `migrate'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/migration.rb:959:in `block in execute_migration_in_transaction'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/migration.rb:1005:in `block in ddl_transaction'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/connection_adapters/abstract/database_statements.rb:202:in `block in transaction'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/connection_adapters/abstract/database_statements.rb:210:in `within_new_transaction'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/connection_adapters/abstract/database_statements.rb:202:in `transaction'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/transactions.rb:209:in `transaction'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/migration.rb:1005:in `ddl_transaction'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/migration.rb:958:in `execute_migration_in_transaction'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/migration.rb:920:in `block in migrate'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/migration.rb:916:in `each'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/migration.rb:916:in `migrate'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/migration.rb:764:in `up'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/migration.rb:742:in `migrate'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/gems/activerecord-4.0.2/lib/active_record/railties/databases.rake:42:in `block (2 levels) in <top (required)>'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/bin/ruby_noexec_wrapper:14:in `eval'
/Users/Alex/.rvm/gems/ruby-2.0.0-p353@sourcebuster/bin/ruby_noexec_wrapper:14:in `<main>'
Tasks: TOP => db:migrate
(See full trace by running task with --trace)

为什么插入失败？

Answer 1

尝试插入此方法

class CreateSourcebusterSources < ActiveRecord::Migration
    def migrate(direction)
        super
        # Create a default Sourcebuster
         Sourcebuster::Source.create! domain: "yahoo.com",
                            source_alias: "yahoo.com",
                            is_social: false,
                            is_organic: true,
                            organic_query_param: "p" if direction == :up
    end
#def change 
   ...
end