cannot execute pivot statement

[l1t1]

main=> PIVOT cities
ON year
USING sum(population);
ERROR:  Invalid Input Error: Cannot prepare multiple statements at once!

[l1t1]

fixed

      auto statements = conn.ExtractStatements(query);

      auto statement_count = statements.size();

  
      for (auto i = 0; i < statement_count - 1; ++i) {
      auto pending = conn.PendingQuery(std::move(statements[i]), true);
      // Return any error found before execution.
      if (pending->HasError()) {
      }
      else
      pending->Execute()->Print();
     }

     auto &statement_to_run = statements[statement_count - 1];
        try {
            prepared = conn.Prepare(std::move(statement_to_run));//(query);