OPP Ass 2 (Rewrite) - Student Database

// TODO: Phone Number Fetching

#include <iostream>
#include <string>
using namespace std;


class Student {
    string name, address, irn, grade, dob;
    int roll;
    char *blood, *div;
    static string university;
public:
    long long phone;
    friend class Contact;
    friend class Database;

    Student(){
        name = "NULL";
        address = "NULL";
        irn = "NULL";
        grade = "NULL";
        roll = 00;
        phone = 0000000000;
        blood = new char[1];
        div = new char[1];
    }

    void setData(){
        cin.ignore();
        blood = new char[4];
        div = new char[4];
        cout << "\nENTER DETAILS ----- ----- ----- ----- ----- -----";
        cout << "\n\nEnter Name: "; getline(cin, name);
        cout << "\nEnter Class (Year and Branch): "; getline(cin, grade);
        cout << "\nEnter Roll: "; cin >> roll;
        cout << "\nEnter Division: "; cin >> div;
        cout << "\nEnter Date of Birth (DD/MM/YYYY): "; cin >> dob;
        cout << "\nEnter Blood Group (A+, A-, B+, B-, AB+, AB-, O+, O-): "; cin >> blood;
        cout << "\nEnter IRN: "; cin >> irn;
        cin.ignore();
        cout << "\nEnter Address: "; getline(cin, address);
    }

    ~Student() {
        delete[] blood;
    }
};


class Contact {
    long long phone;
public:
    void setPhone() {
        try {
            cout << "\nEnter Phone No.: "; cin >> phone;
            if ((phone < 1000000000) or (phone > 9999999999)) {
                cout << "\nERROR! Invalid Phone Number";
                throw (phone);
            }
        } catch (long long phone) {
            cout << "\nEnter a Valid Phone No.: "; cin >> phone;
        }
    }
};


class Database {
public:
    void fetchData(Student &obj){
        cout << "\n\n----- ----- ----- ----- ----- ----- ----- -----";
        cout << "\n\nDETAILS FOR STUDENT: " << obj.name;
        cout << "\nName: " << obj.name;
        cout << "\nClass: " << obj.grade;
        cout << "\nRoll No.: " << obj.roll;
        cout << "\nBlood Group: " << obj.blood;
        cout << "\nPhone No.: " << obj.phone;
        cout << "\nIRN: " << obj.irn;
        cout << "\nAddress: " << obj.address;
        cout << "\nCollege Name: " << Student::university;
        cout << "\n\n----- ----- ----- ----- ----- ----- ----- -----";
    }

    static void fetchCollege() {
        cout << "\nCollege Name: " << Student::university;
    }

    inline int fetchRoll(Student &obj) {
        return obj.roll;
    }
};

string Student::university = "I2IT, Pune";

int main() {

    int n;
    cout << "\nEnter the number of students: "; cin >> n;
    Student students[n];
    Contact contacts[n];
    Database db;



    for (int i = 0; i < n; i++){
        students[i].setData();
        contacts[i].setPhone();
    }


    cout << "\n ----- ----- ----- ----- ----- ----- ----- -----";


    while (true) {
        int choice;
        cout << "\n\n----- MENU ----- ----- ----- ----- ----- -----";
        cout << "\n1: Show All Data\n2: Search by Roll No\n3: Exit";
        cout << "\nEnter choice number: ";
        cin >> choice;

        if (choice == 1) {
            cout << "\n----- SHOWING ALL DATA ----- ----- ----- ----- -----";
            for (int i = 0; i < n; i++) {
                db.fetchData(students[i]);
            }
        }

        else if (choice == 2) {
            while (true) {
                int ROLL, breaker;
                int flag = 0;
                cout << "\nEnter the Roll No. you want to look up (Enter -1 to Exit): "; cin >> ROLL;
                if (ROLL == -1) break;
                else {
                    for (int i = 0; i < n; i++){
                        if (ROLL == db.fetchRoll(students[i])) {
                            db.fetchData(students[i]);
                            flag = 1;
                            break;
                        }
                    }
                    if (!flag) {
                        cout << "\nERROR! Record Not Found";
                        cout << "\nDo you want to Continue? (Enter 1 for Yes, 0 for No): "; cin >> breaker;
                        if (breaker != 1) {
                            break;
                        }

                    }
                }
            }
        }

        else if (choice == 3) {
            cout << "\nTERMINATING PROGRAM\n";
            break;
        }
    }

    return 0;
}