functions.h

#include <iostream>
#include <string>
#include <sqlite3.h>
#include <string.h>

using namespace std;

class timetable_db {

	private:  /// SQLite configuration

    	sqlite3 *db;
    	char *zErrMsg;
    	int rc;
    	char* sql;
    	sqlite3_stmt *stmt;
 
		static int callback(void *NotUsed, int argc, char **argv, char **azColName) {

		    for(int i = 0; i < argc; i++) {		        
		        cout << azColName[i] << ": " << argv[i] << endl;		    
		    }

		    cout << endl;

		    return 0;
		}

		// Testing DB errors
		void errors_db() {   

			if( rc ){
		        cout << "DB Error: " << sqlite3_errmsg(db) << endl;
		        
		        close_db();		        
    		}
		}

	public:

		// Creating DB
		timetable_db() {
    		rc = sqlite3_open("timetable.db", &db);
			errors_db();    		
		}

		// Function to make the tables
		void create_table() {   
		    
			sql = "CREATE TABLE STUDENT (STUDENT_ID INT PRIMARY KEY, STUDENT_NAME VARCHAR(50));";		    
		    rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg);

		    sql = "CREATE TABLE LECTURER (LECTURER_ID INT PRIMARY KEY, LECTURER_NAME VARCHAR(50));";
		    rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg);

		    sql = "CREATE TABLE MODULE (MODULE_ID INT PRIMARY KEY, MODULE_NAME VARCHAR(50));";
		    rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg);

		    sql = "CREATE TABLE ROOM (ROOM_ID INT PRIMARY KEY, ROOM_NAME VARCHAR(50));";
		    rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg);

			sql = "CREATE TABLE CLASS (CLASS_ID INT PRIMARY KEY, CLASS_TIME INT, ROOM_ID INT, LECTURER_ID INT, STUDENT_ID INT, MODULE_ID INT);";
		    rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg);
		}

		// Function to insert data in Students table
		void insert_student(char* ID, char* name) {

			char *query = NULL;

			asprintf(&query, "INSERT INTO STUDENT ('STUDENT_ID', 'STUDENT_NAME') VALUES  ('%s', '%s');", ID, name);   

		    sqlite3_prepare(db, query, strlen(query), &stmt, NULL);

			rc = sqlite3_step(stmt);

			sqlite3_finalize(stmt);

			free(query);     
		}

		// Function to insert data in Lecturers table
		void insert_lecturer(char* ID, char* name) {

			char *query = NULL;

			asprintf(&query, "INSERT INTO LECTURER ('LECTURER_ID', 'LECTURER_NAME') VALUES  ('%s', '%s');", ID, name);   

		    sqlite3_prepare(db, query, strlen(query), &stmt, NULL);

			rc = sqlite3_step(stmt);

			sqlite3_finalize(stmt);

			free(query);     
		}

		// Function to insert data in Modules table
		void insert_module(char* ID, char* name) {

			char *query = NULL;

			asprintf(&query, "INSERT INTO MODULE ('MODULE_ID', 'MODULE_NAME') VALUES  ('%s', '%s');", ID, name);   

		    sqlite3_prepare(db, query, strlen(query), &stmt, NULL);

			rc = sqlite3_step(stmt);

			sqlite3_finalize(stmt);

			free(query);     
		}

		// Function to insert data in Rooms table
		void insert_room(char* ID, char* name) {

			char *query = NULL;

			asprintf(&query, "INSERT INTO ROOM ('ROOM_ID', 'ROOM_NAME') VALUES  ('%s', '%s');", ID, name);   

		    sqlite3_prepare(db, query, strlen(query), &stmt, NULL);

			rc = sqlite3_step(stmt);

			sqlite3_finalize(stmt);

			free(query);     
		}

		// Function to insert data in Classes table
		void insert_class(char* ID, char* class_time, char* room, char* lecturer, char* student, char* module) {

			char *query = NULL;

			asprintf(&query, "INSERT INTO CLASS ('CLASS_ID', 'CLASS_TIME', 'ROOM_ID', 'LECTURER_ID', 'STUDENT_ID', 'MODULE_ID') VALUES  ('%s', '%s', '%s', '%s', '%s', '%s');", ID, class_time, room, lecturer, student, module);  

		    sqlite3_prepare(db, query, strlen(query), &stmt, NULL);

			rc = sqlite3_step(stmt);

			sqlite3_finalize(stmt);

			free(query);     
		}

		// Function the give DB data as output
		void show_db() {

    		sql = "SELECT * FROM 'STUDENT';";
    		rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg);

    		sql = "SELECT * FROM 'LECTURER';";
    		rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg);

			sql = "SELECT * FROM 'MODULE';";
    		rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg);

			sql = "SELECT * FROM 'ROOM';";
    		rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg);

			sql = "SELECT * FROM 'CLASS';";
    		rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg);
		}

		// Closing DB connection
		void close_db() {

    		sqlite3_close(db);
		}
};