method

references

v4.2.1 - Show latest stable - 1 note - Class: ActiveRecord::ConnectionAdapters::TableDefinition

references(*args) public

Adds a reference. Optionally adds a type column, if :polymorphic option is provided. references and belongs_to are acceptable. The reference column will be an integer by default, the :type option can be used to specify a different type. A foreign key will be created if a foreign_key option is passed.

t.references(:user)
t.references(:user, type: "string")
t.belongs_to(:supplier, polymorphic: true)

See SchemaStatements#add_reference

Show source

# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 317
      def references(*args)
        options = args.extract_options!
        polymorphic = options.delete(:polymorphic)
        index_options = options.delete(:index)
        foreign_key_options = options.delete(:foreign_key)
        type = options.delete(:type) || :integer

        if polymorphic && foreign_key_options
          raise ArgumentError, "Cannot add a foreign key on a polymorphic relation"
        end

        args.each do |col|
          column("#{col}_id", type, options)
          column("#{col}_type", :string, polymorphic.is_a?(Hash) ? polymorphic : options) if polymorphic
          index(polymorphic ? %(type id).map { |t| "#{col}_#{t}" } : "#{col}_id", index_options.is_a?(Hash) ? index_options : {}) if index_options
          foreign_key(col.to_s.pluralize, foreign_key_options.is_a?(Hash) ? foreign_key_options : {}) if foreign_key_options
        end
      end

February 17, 2009

2 thanks

See column

See the end part of the docs on column for example uses.

references

Related methods

See column