DBClass.h

#include <iostream>
#include <string>
#include <sqlite3.h>
#include <libc.h>
#include <cstdlib>
using namespace std;
class TimeTable {
    private: //Everything in this private section cannot be accessed from outside of the class
        sqlite3 *db; //Points at SQL Connection
        char *zErrMsg;  //Stores any error messages returned
        int rc; //Stores any response from SQL creation
        const char* sql; //Stores SQL commands
        sqlite3_stmt *stmt; //Stores the combined SQL statement
        static int callback(void *NotUsed, int argc, char **argv, char **azColName){
            for(int i = 0; i<argc; i++){
                cout << azColName[i] << ": " << argv[i] << endl;
            }
            printf("\n");
            return 0;
        } //Call back function to store returns from submitted statements
        void TimeTables(){
        sql = "CREATE TABLE IF NOT EXISTS TimeTables("\
                  "Student_ID       NOT NULL,"\
                  "MODULE_ID        NOT NULL,"\
                  "Class_Name       NOT NULL,"\
                  "Lecturer_ID      NOT NULL,"\
                  "Room_Number      NOT NULL);";
        rc = sqlite3_exec(db, sql, callback, nullptr, &zErrMsg);
    } // Creates an empty timetable if one doesn't exist
        void InsertData(){
        sql = "INSERT INTO TimeTables ('Student_ID', 'MODULE_ID', 'Class_Name', 'Lecturer_ID', 'Room_Number') VALUES ('9783559','4000CEM','Coding with Python','4332613','402');"\
              "INSERT INTO TimeTables ('Student_ID', 'MODULE_ID', 'Class_Name', 'Lecturer_ID', 'Room_Number') VALUES ('9788459','5003CEM','Algorithms','7967999','107');"\
              "INSERT INTO TimeTables ('Student_ID', 'MODULE_ID', 'Class_Name', 'Lecturer_ID', 'Room_Number') VALUES ('5733246','5011CEM','Gantt Charts','2809856','930');"\
              "INSERT INTO TimeTables ('Student_ID', 'MODULE_ID', 'Class_Name', 'Lecturer_ID', 'Room_Number') VALUES ('5813399','5001CEM','Welcome to websites','2262907','343');"\
              "INSERT INTO TimeTables ('Student_ID', 'MODULE_ID', 'Class_Name', 'Lecturer_ID', 'Room_Number') VALUES ('8695248','4007CEM','Databases','8234413','600');";
        rc = sqlite3_exec(db, sql, callback, nullptr, &zErrMsg);
    }   // Predefined Data to fill the timetable
        void InsertDataManual(const char* SID,const char* MID,const char* CN,const char* LID,const char* RN) {
        const char *query = nullptr;
        asprintf(const_cast<char **>(&query), "INSERT INTO TimeTables ('Student_ID', 'MODULE_ID', 'Class_Name', 'Lecturer_ID', 'Room_Number') VALUES ('%s','%s','%s','%s','%s');", SID, MID, CN, LID, RN);
        //Placeholders are used in order to take in a user input straight into the line to run
        sqlite3_prepare(db, query, strlen(query), &stmt, nullptr);
        rc = sqlite3_step(stmt);
        sqlite3_finalize(stmt);
    } // Allows user to insert their own data
        void DBErrors() {
            if (rc) {
                cout << "Data Base Error:" << sqlite3_errmsg(db) << endl;
                closeDB();
            }
        } //Checks if there are any SQL errors after running the SQL command
        //If so the error is printed
    void GetAll(){
        sql = "SELECT * FROM 'TimeTables';";
        rc = sqlite3_exec(db, sql, callback, nullptr, &zErrMsg);
    }//Selects all the values in the timetable
    //-----------------------------------------------------------------------------------------///
    //Isn't functional Yet. This piece of code is created to select a specific timetable
    void SelectStudent(const char* SID){
        const char *query = nullptr;
        asprintf(const_cast<char **>(&query), "SELECT * FROM TimeTables WHERE Student_ID = '%s';", SID);
        sqlite3_prepare(db, query, strlen(query), &stmt, nullptr);
        DBErrors();
        rc = sqlite3_step(stmt);
        DBErrors();
        sqlite3_finalize(stmt);
        DBErrors();
        cout << "Added" << endl;
    } //This function is supposed to allow the user to get personalised timetable
    void Student(){
        string a;
        cout << "Please enter the student's ID:" << endl;
        cin >> a;
        const char* _a = a.c_str();
        SelectStudent(_a);
    }   //This function takes the user's input in the form of Student ID
    //The above two functions function correctly however there is an error that returns from the SQLite connection
    //that couldn't be understood --- More on this in the video vlog
    //----------------------------------------------------------------------------------------///
    void NewData(){
        string a, b, c, d, e;
        cout << "Please enter the student ID:" << endl;
        cin >> a;
        const char* _a = a.c_str();
        cout << "Please enter the Module ID: " << endl;
        cin >> b;
        const char* _b = b.c_str();
        cout << "Please enter the Class Name: " << endl;
        cin >> c;
        const char* _c = c.c_str();
        cout << "Please enter the Lecturer's ID:" << endl;
        cin >> d;
        const char* _d = d.c_str();
        cout << "Please enter the Room Number: " << endl;
        cin >> e;
        const char* _e = e.c_str();
        InsertDataManual(_a,_b,_c,_d,_e);
    } // Takes user input in order to be run with InsertDataManual in order to be executed in SQL
    void Choice(int D){
        string stmnta = "What would you like to do today? \n (A) Check All Classes \n (B) Add New Class \n (C) EXIT \n (D) Add standard uni library to your directory (Recommended)";
        string stmntb = "What would you like to do today? \n (A) Check All Classes \n (B) Add New Class \n (C) EXIT ";
        string stmntc = "Please give your choice in a single alphabet: ";
        string choice;
        if (D != 1){
            cout << stmnta << "\n" << stmntc << endl;
            cin >> choice;
            if (choice == "a" || choice == "A") {
                cout << "You have chosen to check all classes:" << endl;
                GetAll();
                Choice(0);
            }else if (choice == "b" || choice == "B"){
                cout << "You have chosen to add new class:" << endl;
                NewData();
                cout << "New Class Added Successfully!" << endl;
                Choice(0);
            }else if (choice == "c" || choice == "C"){
                cout << "You have chosen to exit. \n Program will shut down shortly. " << endl;
                sleep(4);
                closeDB();
                exit(1);
            }else if (choice == "d" || choice == "D"){
                cout << "You have chosen to add the standard library to your directory. \n Adding Library:...";
                sleep(5);
                InsertData();
                cout << "Library successfully added!" << endl;
                Choice(1);
            }else{
                cout << "What you entered is not recognized. \n Please try again." << endl;
                Choice(0);
            }
        }else {
            cout << stmntb << "\n" << stmntc << endl;
            cin >> choice;
            if (choice == "a" || choice == "A") {
                cout << "You have chosen to check all classes:" << endl;
                GetAll();
                Choice(D);
            }else if (choice == "b" || choice == "B"){
                cout << "You have chosen to add new class:" << endl;
                NewData();
                cout << "New Class Added Successfully!" << endl;
                Choice(D);
            }else if (choice == "c" || choice == "C"){
                cout << "You have chosen to exit. \n Program will shut down shortly. " << endl;
                sleep(4);
                closeDB();
                exit(1);
            }else{
                cout << "What you entered is not recognized. \n Please try again." << endl;
                Choice(D);
            }
        }
    } //This is the user interface console that allows the user to "choose their own adventure"
public: //Everything in here is what can be used by the main file
        TimeTable(){
            rc = sqlite3_open( "Year2", &db);
            DBErrors();
            TimeTables();
        }  //Includes the initiation of the Database
        void Opening(){
            //The use of sleep in this function is two fold first is to give the user enough time to read the messages being pushed out
            //Second it is to give the feeling that this is a heavy program almost at the same speed of any other application
            cout << "Good Morning!" << endl;
            sleep(2);
            cout << "Just 3 seconds while I boot up for your use..." << endl;
            sleep(7);
            cout << "Hello There! \n Thank you for being so Patient! " << endl;
            Choice(0);
        } //This is the primary interface console that welcomes the user and mimics a realistic scenario
        void closeDB(){
            sqlite3_close(db);
        } //Closes the Database after user is done with it to avoid injection
};