code: private function doDeleteTransaction(int $administratorId)
      {
          pg_query("BEGIN");
          try {
              $this->doDeleteAdministratorRoles($administratorId);
          } catch (\Exception $e) {
              pg_query("ROLLBACK");
              throw $e;
          } 
          try {
              $this->administratorsTableMapper->delete($administratorId);
          } catch (\Exception $e) {
              pg_query("ROLLBACK");
              throw $e;
          } 
          pg_query("COMMIT");
      }
docs: any necessary validation should be performed prior to calling