Initial commit. Contains a simple query tool.

PgsqlConn.h

@@ -0,0 +1,196 @@
+#pragma once
+
+#include <functional>
+#include <string>
+#include <pgsql/libpq-fe.h>
+#include <cassert>
+#include <QString>
+
+namespace Pgsql {
+
+	/*
+	This library has multiple layers.
+
+	Layer 1 delivers lowlevel C++ wrappers for the basic libpq functionality. Adding
+	automatic resource management.
+
+	*/
+
+	class ConnectionParams {
+	public:
+		std::string host;
+		std::string hostaddr;
+		unsigned short port = 5432;
+		std::string dbname;
+		std::string user;
+		std::string password;
+		int connect_timeout = -1; ///< -1 omit (ie uses default)
+		std::string application_name;
+
+	};
+
+	/** Non-copyable but movable wrapper for a postgresql result. */
+	class Result {
+	public:
+//		class iterator {
+//		public:
+//			iterator(Result &r, int rw)
+//				: result(r), row(rw)
+//			{}
+
+//			iterator operator++()
+//			{
+//				iterator t(*this);
+//				++row;
+//				return t;
+//			}
+
+//			iterator& operator++(int)
+//			{
+//				++row;
+//				return *this;
+//			}
+
+//			bool operator!=(const iterator &rhs)
+//			{
+//				assert()
+//			}
+
+//		private:
+//			Result &result;
+//			int row;
+//		};
+
+		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 getResultStatus();
+		std::string getResStatus();
+
+
+		int getRows() const;
+		int getCols() const;
+
+		const char* const getColName(int idx) const;
+
+		const char * getVal(int col, int row) const;
+
+//		iterator begin();
+	private:
+		PGresult *result = nullptr;
+	};
+
+	class Connection {
+	public:
+		Connection();
+		~Connection();
+
+		Connection(const Connection &rhs) = delete;
+		Connection& operator=(const Connection &rhs) = delete;
+
+		Connection(Connection &&rhs);
+		Connection& operator=(Connection &&rhs);
+
+//		void connect(const ConnectionParams &params);
+		bool connect(const char *params);
+		bool connect(const QString &params)
+		{
+			return connect(params.toUtf8().data());
+		}
+
+		void close();
+
+		std::string getErrorMessage() const;
+
+        Result Query(const char * query);
+		Result Query(const QString &query)
+		{
+			return Query(query.toUtf8().data());
+		}
+
+	private:
+		PGconn *conn = nullptr;
+	};
+
+	class Canceller {
+	public:
+		void Cancel();
+	};
+
+
+
+	class Field {
+	public:
+
+		std::string getName() const;
+
+	private:
+		//Tuples tuples;
+		int field;
+		//
+
+	};
+
+	class Tuples {
+	public:
+		int getRowCount() const;
+		int getColCount() const;
+
+		Field getField(const std::string &fname);
+		Field getField(const int idx);
+
+		class const_iterator {
+		public:
+            const_iterator& operator++();
+		};
+
+		void rewind();
+
+
+	};
+
+	class OkResult: public Result {
+	public:
+		/** If the result is a data result then returns an interface for processing this data.
+
+		The returned interface remains valid as long as this OkResult exists.
+		*/
+		Tuples* hasTuples();
+	};
+
+//	class ErrorResult: public Result {
+//
+//	};
+
+//	class ITransaction {
+//	public:
+//
+//		Canceller Query(std::string query,
+//			std::function<void(OkResult)> on_success,
+//			std::function<void()> on_cancelled,
+//			std::function<void(ErrorResult)> on_error);
+//
+//		Canceller Query(std::string query,
+//			std::function<void(OkResult)> on_success,
+//			std::function<void()> on_cancelled,
+//			std::function<void(ErrorResult)> on_error);
+//
+//
+//		void Rollback(
+//			std::function<void(OkResult)> on_success,
+//			std::function<void(ErrorResult)> on_error);
+//		void Commit(
+//			std::function<void(OkResult)> on_success,
+//			std::function<void()> on_cancelled,
+//			std::function<void(ErrorResult)> on_error);
+//
+//	};
+}