Can ActiveRecord create tables outside of a migration?
I am working on a non Rails web app, so no migrations script by default.
The Sequel ORM lets me create tables easily in a script:
#!/usr/bin/env ruby require 'rubygems' require 'sequel' ## Connect to the database DB = Sequel.sqlite('./ex1.db') unless DB.table_exists? :posts DB.create_table :posts do primary_key :id varchar :title text :body end end
Is there a way todo this with ActiveRecord outside of migrations?
My current understanding is no, all modifications data or schema have to be done through a migration. I have a complete rakefile on github which can be used to perform the migrations outside of Rails.
Alternatively if it is just an initialisation script the following could be used.
ActiveRecord::Base.establish_connection( :adapter => 'sqlite3', :database => './lesson1_AR.db' ) ActiveRecord::Migration.class_eval do create_table :posts do |t| t.string :title t.text :body end create_table :people do |t| t.string :first_name t.string :last_name t.string :short_name end create_table :tags do |t| t.string :tags end end
In Rails 4 at least (possibly earlier?), you can call create table directly on an ActiveRecord::ConnectionAdapters instance, using the same syntax as the migration.
You can get a connection for your database (assuming you have only one database) by calling ActiveRecord::Base.connection. So, the Ruby for your example would look like:
unless ActiveRecord::Base.connection.table_exists?(:posts) ActiveRecord::Base.connection.create_table :posts do |t| # :id is created automatically t.string :title t.text :body end end
Note: If you already have a model defined, and it uses the same database as the one in which you want to create the table, you can grab a connection object from there instead. For one-off table creation in the console, I'll call User.connection.create_table simply because it's less typing.