pgLab/src/Pgsql_Result.h

#ifndef PGSQL_RESULT_H
#define PGSQL_RESULT_H

#include "Pgsql_Row.h"

namespace Pgsql {

	class ErrorDetails {
	public:
		static ErrorDetails createErrorDetailsFromPGresult(const PGresult *res);

		std::string errorMessage;
		std::string state; ///< PG_DIAG_SQLSTATE Error code as listed in	https://www.postgresql.org/docs/9.5/static/errcodes-appendix.html
		std::string severity;
		std::string messagePrimary;
		std::string messageDetail;
		std::string messageHint;
		int statementPosition; ///< First character is one, measured in characters not bytes!
		int internalPosition;
		std::string internalQuery;
		std::string context;
		std::string schemaName;
		std::string tableName;
		std::string columnName;
		std::string datatypeName;
		std::string constraintName;
		std::string sourceFile;
		std::string sourceLine;
		std::string sourceFunction;
	};

	/** \brief Non-copyable but movable wrapper for a postgresql result.
	 *
	 * This class makes sure the result is removed from memory. It also supplies an iterator for the
	 * rows from the result facilitating also the use of the cpp for each.
	 */
	class Result {
	public:
		class const_iterator {
		public:
			const_iterator(const Result &r, int rw)
				: m_row(r, rw)
			{}

			const_iterator operator++()
			{
				const_iterator t(*this);
				m_row.next();
				return t;
			}

			const_iterator& operator++(int)
			{
				m_row.next();
				return *this;
			}

			bool operator==(const const_iterator &rhs)
			{
				return m_row == rhs.m_row;
			}

			bool operator!=(const const_iterator &rhs)
			{
				return !operator==(rhs);
			}

			const Row& operator*()
			{
				return m_row;
			}
			const Row& operator->()
			{
				return m_row;
			}

		private:
			Row m_row;
		};

		Result() = default;
		Result(PGresult *result);
		~Result();

		Result(const Result &rhs) = delete;
		Result& operator=(const Result &rhs) = delete;

		Result(Result &&rhs);
		Result& operator=(Result &&rhs);

		operator bool() const;

		ExecStatusType resultStatus();

		std::string getResStatus();

		/** Use this to retrieve an error code when this is an error result
		 *
		 * The possible code are listed in https://www.postgresql.org/docs/9.5/static/errcodes-appendix.html
		 */
		std::string diagSqlState();
		/** Retrieves all the error fields. */
		ErrorDetails diagDetails();

		const_iterator begin() const
		{
			return const_iterator(*this, 0);
		}

		const_iterator end() const
		{
			return const_iterator(*this, rows());
		}

		int tuplesAffected() const;
		int rows() const;
		int cols() const;

		const char* const getColName(int idx) const;

		const char * val(int col, int row) const;
		Value get(int col, int row) const;
		Oid type(int col) const;
		bool null(int col, int row) const;


	//		iterator begin();
	private:
		PGresult *result = nullptr;
	};


} // end namespace Pgsql

#endif // PGSQL_RESULT_H