require 'active_support/core_ext/object/blank'
module ActiveRecord
# = Active Record Schema
#
# Allows programmers to programmatically define a schema in a portable
# DSL. This means you can define tables, indexes, etc. without using SQL
# directly, so your applications can more easily support multiple
# databases.
#
# Usage:
#
# ActiveRecord::Schema.define do
# create_table :authors do |t|
# t.string :name, :null => false
# end
#
# add_index :authors, :name, :unique
#
# create_table :posts do |t|
# t.integer :author_id, :null => false
# t.string :subject
# t.text :body
# t.boolean :private, :default => false
# end
#
# add_index :posts, :author_id
# end
#
# ActiveRecord::Schema is only supported by database adapters that also
# support migrations, the two features being very similar.
class Schema < Migration
def migrations_paths
ActiveRecord::Migrator.migrations_paths
end
# Eval the given block. All methods available to the current connection
# adapter are available within the block, so you can easily use the
# database definition DSL to build up your schema (+create_table+,
# +add_index+, etc.).
#
# The +info+ hash is optional, and if given is used to define metadata
# about the current schema (currently, only the schema's version):
#
# ActiveRecord::Schema.define(:version => 20380119000001) do
# ...
# end
def self.define(info={}, &block)
schema = new
schema.instance_eval(&block)
unless info[:version].blank?
initialize_schema_migrations_table
assume_migrated_upto_version(info[:version], schema.migrations_paths)
end
end
end
end
