Class: ActiveRecord::Schema

Inherits:

Migration::Current

• Object
• Migration
• Migration::Current
• ActiveRecord::Schema

Includes:

Definition

Defined in:

lib/active_record/schema.rb

Overview

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[7.0].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.

Defined Under Namespace

Modules: Definition

Constant Summary

Constants inherited from Migration

Migration::MigrationFilenameRegexp

Instance Attribute Summary

Attributes inherited from Migration

#name, #version

Class Method Summary

• .[](version) ⇒ Object

Methods included from Definition

#define

Methods inherited from Migration::Current

#change_table, #compatible_table_definition, #create_join_table, #create_table, #drop_table

Methods inherited from Migration

#announce, check_all_pending!, check_pending_migrations, #connection, #connection_pool, #copy, current_version, #disable_ddl_transaction, disable_ddl_transaction!, #down, #exec_migration, #execution_strategy, inherited, #initialize, load_schema_if_pending!, maintain_test_schema!, method_missing, #method_missing, migrate, #migrate, nearest_delegate, #next_migration_number, #proper_table_name, #reversible, #revert, #reverting?, #run, #say, #say_with_time, #suppress_messages, #table_name_options, #up, #up_only, valid_version_format?, #verbose, #write

Constructor Details

This class inherits a constructor from ActiveRecord::Migration

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class ActiveRecord::Migration

Class Method Details

.[](version) ⇒ Object

# File 'lib/active_record/schema.rb', line 70

def self.[](version)
  @class_for_version ||= {}
  @class_for_version[version] ||= Class.new(Migration::Compatibility.find(version)) do
    include Definition
  end
end