method

references

v3.0.9 - Show latest stable - Class: ActiveRecord::ConnectionAdapters::Table

references(*args)

public

Adds a reference. Optionally adds a type column. references and belongs_to are acceptable.

Examples

t.references(:goat)
t.references(:goat, :polymorphic => true)
t.belongs_to(:goat)

# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 678
      def references(*args)
        options = args.extract_options!
        polymorphic = options.delete(:polymorphic)
        args.each do |col|
          @base.add_column(@table_name, "#{col}_id", :integer, options)
          @base.add_column(@table_name, "#{col}_type", :string, polymorphic.is_a?(Hash) ? polymorphic : options) unless polymorphic.nil?
        end
      end

2Notes

Doesn't add an index

avit · Aug 22, 20084 thanks

Typically you will want to have an index on foreign keys but this method doesn't assume that. Outside of the create_table block you should follow this with add_index :

add_index :table_name, :goat_id
# and, if polymorphic:
add_index :table_name, :goat_type

add index directly

apsoto · Apr 23, 2015

You can add an index now directly on the foreign_key :

t.references(:user, index: true)

references

Examples

2Notes

Doesn't add an index

add index directly

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