properly_disable_ri

properly_disable_ri.rb

# Hack to disable_referential_integrity for postgres users with sane 
# permissions, uses deferral of constraints instead of disablement of the 
# superuser-owned per-table triggers. Allows testing with fixtures which 
# otherwise produce RI_ConstraintTrigger Errors.
#
# source: http://kopongo.com/2008/7/25/postgres-ri_constrainttrigger-error
# ref: https://github.com/matthuhiggins/foreigner/issues/61

module ActiveRecord
  module ConnectionAdapters
    class PostgreSQLAdapter < AbstractAdapter

      alias_method :supports_deferring_all_constraints?, :supports_disable_referential_integrity?
      def defer_all_constraints(&block)
        return unless supports_deferring_all_constraints?

        transaction do
          begin
            execute "SET CONSTRAINTS ALL DEFERRED"
            yield
          ensure
            execute "SET CONSTRAINTS ALL IMMEDIATE"
          end
        end
      end
      alias_method :disable_triggers_on_each_table, :disable_referential_integrity
      alias_method :disable_referential_integrity, :defer_all_constraints

    end
  end
end