translate_exception

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 1146
        def translate_exception(exception, message)
          case exception.result.error_field(PGresult::PG_DIAG_SQLSTATE)
          when UNIQUE_VIOLATION
            RecordNotUnique.new(message, exception)
          when FOREIGN_KEY_VIOLATION
            InvalidForeignKey.new(message, exception)
          else
            super
          end
        end