Sqlite.h

///////////////////////////////////////////////////////////////////////////////////////////////////
//
// Sqlite.h
//
// Implements integration with SQLite3 database. Dynamically loads the library. Example integration
// is in Database.h/Database.cpp file.
//
///////////////////////////////////////////////////////////////////////////////////////////////////

#ifndef __SQLITE_H__
#define __SQLITE_H__

///////////////////////////////////////////////////////////////////////////////////////////////////
// Header section

#include <functional>
#include "Core/Plugin/Plugin.h"
#include "Core/Log/Log.h"

///////////////////////////////////////////////////////////////////////////////////////////////////
// Class & Structures definition

namespace Engine
{
    /// <summary>
    /// Sqlite class
    ///
    /// Integrates with SQLite3 database.
    /// </summary>
    class Sqlite
    {
    private:
        /// <summary>Pointer to log</summary>
        Log* mLog;

        /// <summary>Pointer to plugin module (work with dynamic libraries)</summary>
        Plugin* mPlugin;

        /// <summary>Sqlite db handle</summary>
        void* mHandle;

        /// <summary>
        /// Opens database connection to SQLite3 file
        /// </summary>
        /// <param name="filename">Database filename</param>
        /// <param name="ppDb">SQLite db handle</param>
        /// <returns>0 on success, non-0 otherwise (see Sqlite error codes)</returns>
        int (*sqlite3_open)(const char* filename, void** ppDb);

        /// <summary>
        /// Close database connection
        /// </summary>
        /// <param name="ppDb">SQLite db handle</param>
        /// <returns>0 on success, non-0 otherwise (see Sqlite error codes)</returns>
        int (*sqlite3_close)(void* ppDb);

        /// <summary>
        /// Execute SQL query
        ///
        /// Note: Callback function is called for each row in the result set, its parameters are:
        /// - User data passed in as 3rd argument to sqlite3_exec
        /// - Number of columns in the result set
        /// - Array of strings representing fields in the current row
        /// - Array of strings representing column names
        /// </summary>
        /// <param name="ppDb">SQLite db handle</param>
        /// <param name="sql">SQL query</param>
        /// <param name="callback">Callback function</param>
        /// <param name="userdata">User data</param>
        /// <param name="errmsg">Error message</param>
        int (*sqlite3_exec)(void* ppDb, const char* sql, int(*callback)(void*, int, char**, char**), void* userdata, char** errmsg);

        /// <summary>
        /// Return english-language text describing the most recent db error
        /// </summary>
        /// <param name="ppDb">SQLite db handle</param>
        /// <returns>Error message</returns>
        char* (*sqlite3_errmsg)(void* ppDb);

    public:
        /// <summary>
        /// Default constructor
        ///
        /// Opens sqlite3.dll and loads its functions
        /// </summary>
        /// <param name="log">Logging system</param>
        Sqlite(Log* log);

        /// <summary>
        /// Default destructor
        /// </summary>
        ~Sqlite();

        /// <summary>
        /// Open database connection
        /// </summary>
        /// <param name="filename">File with sqlite database</param>
        /// <returns>True when connection is successful, false otherwise</returns>
        bool Open(const std::string& filename);

        /// <summary>
        /// Close database connection
        /// </summary>
        void Close();

        /// <summary>
        /// Perform database query
        ///
        /// Note: Callback function is called for each row in the result set, its parameters are:
        /// - User data passed in as last argument to Query
        /// - Number of columns in the result set
        /// - Array of strings representing fields in the current row
        /// - Array of strings representing column names
        /// </summary>
        /// <param name="query">SQL query</param>
        /// <param name="callback">Callback for each processed row</param>
        /// <param name="userdata">Pointer to used data sent into callback function as 1st argument</param>
        void Query(const std::string& query, int(*callback)(void*, int, char**, char**), void* userdata);
    };
}

///////////////////////////////////////////////////////////////////////////////////////////////////
// EOH

#endif