v4.2.9 - Show latest stable - 1 note - Class: ActiveRecord::ConnectionAdapters::SchemaStatements
add_reference(table_name, ref_name, options = {}) public

Adds a reference. The reference column is an integer by default, the :type option can be used to specify a different type. Optionally adds a _type column, if :polymorphic option is provided. add_reference and add_belongs_to are acceptable.

The options hash can include the following keys:


The reference column type. Defaults to :integer.


Add an appropriate index. Defaults to false.


Add an appropriate foreign key. Defaults to false.


Wether an additional _type column should be added. Defaults to false.

Create a user_id integer column
add_reference(:products, :user)
Create a user_id string column
add_reference(:products, :user, type: :string)
Create supplier_id, supplier_type columns and appropriate index
add_reference(:products, :supplier, polymorphic: true, index: true)
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June 7, 2016
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foreign_key option

It is also possible to specify that add_foreign_key should be added to the schema:

add_reference(:products, :supplier, foreign_key: true)