Database Project -
Identify and implement classes for your database
Object Oriented Database
class student{
public:
string fname, lname, major;
double gpa;
int courseId[3]; //course ids *primary key
}; //student
Add to Student Class the courseID
Modify:
addStudent() - Ask the id of courses taken
load() - for student.txt, read courseIds
ex. studentFile>>s[n].fname>>s[n].lname>>s[n].major>>s[n].gpa>>s[n].courseId[0]>>s[n].courseId[1]>>s[n].courseId[2]
store() - for students.txt, write courseIds
ex.
studentFile<<s[i].fname<<" "<<s[i].lname<<"
"<<s[i].major<<" "<<s[i].gpa
<<" "<<s[i].courses[0]<<" "<<s[i].courses[1]<<" "<<s[i].courses[2]<<endl;
students.txt - add course ids to student record
Create Report (ex. Transcript listing
Student Info and Courses)
Example: Classes
Bank Database - data
(Customers, Accounts) and
functions (account statement, add customer,
create account)
Customer (id, name, address, Account numbers array)
Account (account number,
balance):
Subclasses -
Savings, Checking, CD, MoneyMkt
Sample C++ Student Database:
#include<fstream>
#include<string>
#include<iostream>
#include<iomanip>
using namespace std;
class course{
public:
string CRN;
string title;
string department;
string room;
}; //course
class student{
public:
string fname, lname, major;
double gpa;
}; //student
class university{
private:
student e[100];
course c[100];
int n;
int z;
public:
void load(){
n=0;
z=0;
ifstream studentFile("students.txt", ios::in);
ifstream courseFile("courses.txt", ios::in);
while(studentFile>>e[n].fname>>e[n].lname>>e[n].major>>e[n].gpa){
n++;}//WHILE
while(courseFile>>c[z].CRN>>c[z].title>>c[z].department>>c[z].room){
z++;}//WHILE
}//LOAD
void store(){
ofstream studentFile("students.txt",ios::out);
for(int i=0; i<n; i++){
if(e[i].fname!=" ")
studentFile<<e[i].fname<<" "<<e[i].lname<<" "<<e[i].major<<" "<<e[i].gpa<<endl;
}//FOR
ofstream courseFile("courses.txt", ios::out);
for(int j=0; j<z; j++){
if(c[j].CRN!=" ")
courseFile<< c[j].CRN << " "<<c[j].title << " "<<c[j].department << " "<<c[j].room<<endl;
}//FOR
}//STORE
void insert(){
cout<<"Enter student's first name: "; cin>>e[n].fname;
cout<<"Enter student's last name: "; cin>>e[n].lname;
cout<<"Enter student's major: "; cin>>e[n].major;
if(cin.fail()){
cout<<"Error\n"; exit(1);}
cout<<"Enter studen's gpa: ";
cin>>e[n].gpa;
n++;
}//INSERTS THE RECORD TO ARRAY
void addCourse( ){
cout<<"Enter course CRN: ";
cin>>c[z].CRN;
cout<<"Enter course title: ";
cin>>c[z].title;
cout<<"Enter course room: ";
cin>>c[z].room;
cout<<"Enter course department: ";
cin>>c[z].department;
z++;
}//addCourse
int searchCourse(string crn){
for(int i=0;i<z;i++) if(crn==c[i].CRN) return i;//FOR
return -1;
}//SEARCH COURSE BY CRN
void display(){
cout<<setiosflags(ios::left)<<setw(15)<<"First Name"<<setw(15)<<"Last Name";
cout<<setw(10)<<"Major"<<setw(10)<<"GPA";
cout<<endl<<endl;
cout<<setiosflags(ios::fixed|ios::showpoint|ios::left);
for(int i=0;i<n;i++){
if(e[i].fname!=" "){
cout<<setiosflags(ios::left)<<setw(15)<<e[i].fname<<setw(15)<<e[i].lname;
cout<<setprecision(2)<<setiosflags(ios::left)<<setw(10)<<e[i].major;
cout<<setw(10)<<e[i].gpa;
cout<<resetiosflags(ios::left)<<endl;}//IF
}//FOR
}//THIS FUNCTION DISPLAYS ALL RECORDS IN ARRAY
int search(string s){
for(int i=0;i<n;i++) if(s==e[i].lname) return i;//FOR
return -1;
}//SEARCH BY NAME,-1 NOT FOUND
void update(){
string searchn;
cout<<"Enter the Last Name of the Student to be modified: "; cin>>searchn;
int i=search(searchn);
if(i==-1) cout<<"STUDENT NOT LISTED"<<endl;
else{
cout<<endl<<"Please enter the updated information."<<endl;
cout<<"Enter student's first name: "; cin>>e[i].fname;
cout<<"Enter student's last name: "; cin>>e[i].lname;
cout<<"Enter major: "; cin>>e[i].major;
cout<<"Enter gpa: "; cin>>e[i].gpa;
}//ELSE
}//UPDATE
void deletefile(){
int pword;
cout<<"Enter your administrative password: "; cin>>pword;
if(pword==5438){
ofstream record("students.txt", ios::out);
record<<endl;
load();
record.close();}
else cout<<"Wrong password entered."<<endl;
}//DELETE FILE
void backupfile(){
system("copy students.txt backup.txt");
cout<<endl<<"Back-up file has been made."<<endl;
}//BACKUPFILE use cp command for UNIX
void studentmenu(){
char choice='z';
system("cls");
cout<<"Student Menu"<<endl<<endl;
cout<<"1. Insert Student Record"<<endl;
cout<<"2. Display All Records"<<endl;
cout<<"3. Search by Last Name"<<endl;
cout<<"4. Search by Student ID"<<endl;
cout<<"5. Update Record"<<endl;
cout<<"8. Delete Database File"<<endl;
cout<<"9. Back-up Database File"<<endl;
cin>>choice;
switch (choice){
case '1': insert(); break;
case '2': display(); break;
case '3':
char s[100]; int index;
cout<<"Enter the last name of the student you want: ";
cin>>s;
index=search(s);
if(index!=-1) {
cout<<"Name: "<<e[index].fname<<" "<<e[index].lname<<endl;
cout<<"Major: "<<e[index].major<<endl;
cout<<"GPA: "<<e[index].gpa<<endl;
}//IF
else cout<<"STUDENT NOT FOUND"<<endl;
break;
case '4':
int id;
cout<<"Enter Student ID: " ;
cin>>id;
if(id < n){
cout<<"Name: "<<e[id].fname<<" "<<e[id].lname<<endl;
cout<<"Major: "<<e[id].major<<endl;
cout<<"GPA: "<<e[id].gpa; }
else cout<<"Student not found"<<endl;
break;
case '5': update(); break;
case 'e': store(); break; //EXIT
default: cout<<"Invalid Choice"<<endl; break; }//SWITCH
}//studentmenu
void coursemenu(){
char choice='z';
system("cls");
cout<<"Course Menu"<<endl;
cout<<"Add Course (a)"<<endl;
cout<<"Search for Course (s)"<<endl;
cin>>choice;
switch(choice){
case 'a': addCourse(); break;
case 's':
char crn[100]; int index;
cout<<"Enter the CRN of the course: ";
cin>>crn;
index=searchCourse(crn);
if(index!=-1) {
cout<<"CRN: "<<c[index].CRN<<endl;
cout<<"Title: "<<c[index].title<<endl;
cout<<"Room: "<<c[index].room<<endl;
cout<<"Department: "<<c[index].department<<endl;
}//IF
else cout<<"COURSE NOT FOUND"<<endl;
break;break;
default: cout<<"Invalid Choice"<<endl; break;
}//SWITCH
}//coursemenu
};
void main(){
university OW;
OW.load();
char choice='z';
while (choice!='e'&&choice!='E'){
cout<<endl<<"SUNY OW Database"<<endl<<endl;
cout<<"Student Menu (s)"<<endl;
cout<<"Course Menu (c)"<<endl;
cout<<endl<<" Type e to exit"<<endl<<endl;
cin>>choice;
switch(choice){
case 's':
OW.studentmenu();
break;
case 'c':
OW.coursemenu();
break;
case 'e': OW.store(); break; //EXIT
default: cout<<"Invalid Choice"<<endl; break; }//SWITCH
}//WHILE
}//MAIN