remove_foreign_key

Removes the given foreign key from the table. Any option parameters provided will be used to re-add the foreign key in case of a migration rollback. It is recommended that you provide any options used when creating the foreign key so that the migration can be reverted properly.

Removes the foreign key on accounts.branch_id.

remove_foreign_key :accounts, :branches

Removes the foreign key on accounts.owner_id.

remove_foreign_key :accounts, column: :owner_id

Removes the foreign key on accounts.owner_id.

remove_foreign_key :accounts, to_table: :owners

Removes the foreign key named special_fk_name on the accounts table.

remove_foreign_key :accounts, name: :special_fk_name

Checks if the foreign key exists before trying to remove it. Will silently ignore indexes that don’t exist.

remove_foreign_key :accounts, :branches, if_exists: true

The options hash accepts the same keys as SchemaStatements#add_foreign_key with an addition of

:to_table

The name of the table that contains the referenced primary key.

# File activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb, line 1181
      def remove_foreign_key(from_table, to_table = nil, **options)
        return unless use_foreign_keys?
        return if options.delete(:if_exists) == true && !foreign_key_exists?(from_table, to_table)

        fk_name_to_delete = foreign_key_for!(from_table, to_table: to_table, **options).name

        at = create_alter_table from_table
        at.drop_foreign_key fk_name_to_delete

        execute schema_creation.accept(at)
      end