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
def define(info, &block)
@using_deprecated_version_setting = info[:version].present?
SchemaMigration.drop_table
initialize_schema_migrations_table
instance_eval(&block)
# handle files from pre-4.0 that used :version option instead of dumping migration table
assume_migrated_upto_version(info[:version], migrations_paths) if @using_deprecated_version_setting
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.).
def self.define(info={}, &block)
new.define(info, &block)
end
# Create schema migration history. Include migration statements in a block to this method.
#
# migrations do
# migration 20121128235959, "44f1397e3b92442ca7488a029068a5ad", "add_horn_color_to_unicorns"
# migration 20121129235959, "4a1eb3965d94406b00002b370854eae8", "add_magic_power_to_unicorns"
# end
def migrations
raise(ArgumentError, "Can't set migrations while using :version option") if @using_deprecated_version_setting
yield
end
# Add a migration to the ActiveRecord::SchemaMigration table.
#
# The +version+ argument is an integer.
# The +fingerprint+ and +name+ arguments are required but may be empty strings.
# The migration's +migrated_at+ attribute is set to the current time,
# instead of being set explicitly as an argument to the method.
#
# migration 20121129235959, "4a1eb3965d94406b00002b370854eae8", "add_magic_power_to_unicorns"
def migration(version, fingerprint, name)
SchemaMigration.create!(version: version, migrated_at: Time.now, fingerprint: fingerprint, name: name)
end
end
end
