instance method `add_reference`

Ruby on Rails 4.1.16

Since v4.0.13

Available in: v4.0.13 v4.1.16 v4.2.9 v5.2.8.1 v6.0.6 v6.1.7.10 v7.0.10 v7.1.6 v7.2.3 v8.0.4 v8.1.2

Compare with:

add_reference(table_name, ref_name, options = {})

Adds a reference. Optionally adds a type column, if :polymorphic option is provided. add_reference and add_belongs_to are acceptable.

Create a user_id column

add_reference(:products, :user)

Create a supplier_id and supplier_type columns

add_belongs_to(:products, :supplier, polymorphic: true)

Create a supplier_id, supplier_type columns and appropriate index

add_reference(:products, :supplier, polymorphic: true, index: true)

Parameters

table_name req
ref_name req
options opt = {}

Source

# File activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb, line 619
      def add_reference(table_name, ref_name, options = {})
        polymorphic = options.delete(:polymorphic)
        index_options = options.delete(:index)
        add_column(table_name, "#{ref_name}_id", :integer, options)
        add_column(table_name, "#{ref_name}_type", :string, polymorphic.is_a?(Hash) ? polymorphic : options) if polymorphic
        add_index(table_name, polymorphic ? %w[id type].map{ |t| "#{ref_name}_#{t}" } : "#{ref_name}_id", index_options.is_a?(Hash) ? index_options : {}) if index_options
      end

Defined in activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb line 619 · View on GitHub · Improve this page · Find usages on GitHub

Defined in ActiveRecord::ConnectionAdapters::SchemaStatements

Signature

Create a user_id column

Create a supplier_id and supplier_type columns

Create a supplier_id, supplier_type columns and appropriate index

Parameters