module ActiveRecord
# 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.column :name, :string, :null => false
# end
#
# add_index :authors, :name, :unique
#
# create_table :posts do |t|
# t.column :author_id, :integer, :null => false
# t.column :subject, :string
# t.column :body, :text
# t.column :private, :boolean, :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
private_class_method :new
# 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 (like the schema's version):
#
# ActiveRecord::Schema.define(:version => 15) do
# ...
# end
def self.define(info={}, &block)
instance_eval(&block)
unless info.empty?
initialize_schema_information
cols = columns('schema_info')
info = info.map do |k,v|
v = quote(v, cols.detect { |c| c.name == k.to_s })
"#{k} = #{v}"
end
update "UPDATE schema_info SET #{info.join(", ")}"
end
end
end
end
