libfossdbQueryResult.hpp

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/*
 Author: Daniele Fognini
 SPDX-FileCopyrightText: © 2014-2015 Siemens AG
 
 SPDX-License-Identifier: GPL-2.0-only
*/
 
#ifndef LIBFOSSDBQUERYRESULT_HPP_
#define LIBFOSSDBQUERYRESULT_HPP_
 
#include "libfossdbmanager.h"
 
#include "uniquePtr.hpp"
 
#include <vector>
 
namespace fo {
  class PGresultDeleter {
  public:
    void operator()(PGresult* p) {
      PQclear(p);
    }
  };
 
  class QueryResult {
    friend class DbManager;
 
    friend class AgentDatabaseHandler;
 
  private:
    QueryResult(PGresult* ptr);
 
  public:
    QueryResult(QueryResult&& o): ptr(std::move(o.ptr)) {};
 
    bool isFailed() const;
 
    operator bool() const {
      return !isFailed();
    };
 
    int getRowCount() const;
 
    std::vector<std::string> getRow(int i) const;
 
    template<typename T>
    std::vector<T> getSimpleResults(int columnN, T (functionP)(const char*)) const;
 
  private:
    unptr::unique_ptr <PGresult, PGresultDeleter> ptr;   
  };
 
  template<typename T>
  std::vector<T> QueryResult::getSimpleResults(int columnN, T (functionP)(const char*)) const {
    std::vector<T> result;
 
    if (ptr) {
      PGresult* r = ptr.get();
 
      if (columnN < PQnfields(r)) {
        for (int i = 0; i < getRowCount(); i++) {
          result.push_back(functionP(PQgetvalue(r, i, columnN)));
        }
      }
    }
 
    return result;
  }
}
#endif