Database Management System (Using Tree)
On
Wednesday, August 4, 2010
0
comments
/*******************************************************
APPLICATION : Database Management System (Using Tree)
CODED BY : Ankit Pokhrel
COMPILED ON : Borland C++ Ver 5.02
DATE : 2010 - August - 01
********************************************************/
#include "fstream.h"
#include "stdio.h"
#include "conio.h"
#include "string.h"
#include "process.h"
#include "iomanip.h"
/*************** Class Student Section *****************/
class student
{
private:
int roll;
char name[20],faculty[15];
float marks;
public:
student() //initialize data with default constructor
{
roll = 0;
strcpy(name,"");
strcpy(faculty,"");
marks = 0.0;
}
student(int rn,char nme[],char fact[],float mks)
{
roll = rn;
strcpy(name,nme);
strcpy(faculty,fact);
marks = mks;
}
friend istream & operator >> (istream &,student &); //Read
friend ostream & operator << (ostream &,student &); //Print
int getroll()
{ return roll; }
void editRoll(int r)
{ roll = r; }
~student()
{}
};
istream & operator >> (istream &in,student &s)
{
cout << setw(35) << "Roll NO : ";
in >> s.roll;
cin.ignore();
cout << endl << setw(32) << "Name : ";
in.getline(s.name,20);
cout << endl << setw(35) << "Faculty : ";
in >> s.faculty;
cout << endl << setw(33) << "Marks : ";
in >> s.marks;
return in;
}
ostream & operator << (ostream &out,student &s)
{
out << setw(15) << s.roll;
out << setw(20) << s.name;
out << setw(20) << s.faculty;
out << setw(15) << s.marks;
return out;
}
void errorMsg()
{
cout << endl << setw(55) << "Error while Accessing the Database";
getch();
exit(0);
}
/*********** Tree Section *************/
struct TREE //structure to represent a tree
{
int key,address;
struct TREE *right,*left,*root;
};
typedef TREE tree;
tree *New;
char flenme[15];
void create() //function to create a node
{
New = new tree;
New -> left = NULL;
New -> right = NULL;
}
void insert(int Item,int adr,tree *&t)
{
if(t == NULL) //if tree doesn't exists
{
t = new tree; //create a tree
t -> key = Item; //insert data
t -> address = adr;
t -> left = NULL;
t -> right = NULL;
t -> root = t; //initialize root
return;
}
tree *trav = t;
if(Item < trav -> key)
{
if(trav -> left == NULL)
{
create();
New -> key = Item;
New -> address = adr;
trav -> left = New;
}
else
insert(Item,adr,trav -> left); //go to left
}
else
{
if(trav -> right == NULL)
{
create();
New -> key = Item;
New -> address = adr;
trav -> right = New;
}
else
insert(Item,adr,trav -> right); //go to right
}
}
void inorder(tree *t)
{
student s;
ifstream infile(flenme);
if(infile.fail())
errorMsg();
if(t != NULL)
{
inorder(t -> left);
infile.seekg(t -> address);
infile.read((char *) &s,sizeof(s));
if(s.getroll() != -1)
{
cout << s;
cout << endl << endl << endl;
}
inorder(t -> right);
}
}
/*********** Class Database Section ************/
class Database
{
private:
char *filename;
public:
Database()
{
filename = new char[15];
strcpy(filename,"");
}
int isDBloaded();
int createDB();
int CheckPrimaryKey(int,tree *);
void Add(student,tree *&);
void Remove(int,tree *&);
void Search(int,tree *&);
void Modify(int,tree *&);
void Clear();
void Help();
~Database()
{ delete filename; }
};
int Database :: isDBloaded()
{
if(strcmp(filename,"") != 0)
return 1;
else
return 0;
}
int Database :: createDB() //Function to create a Database
{
char fname[15];
cout << endl << setw(47) << "Enter Database Name : ";
cin >> fname;
student s;
ifstream infile(fname);
ofstream outfile;
if(infile.fail())
{
cout << endl << endl << setw(50) << "Database Doesn't Exist...";
cout << endl << setw(50) << "Press Enter to create...";
if(getch() == 13)
{
strcpy(filename,fname);
outfile.open(fname);
if(outfile.fail())
errorMsg();
else
{
strcpy(flenme,filename);
cout << "\n\n" << setw(46) << "Database Created";
cout << endl << setw(53) << "Press any key to continue...";
}
outfile.close();
return -1; //Database just created
}
else
return 0; //Database was not created
}
strcpy(filename,fname);
strcpy(flenme,filename);
int add = -1;
while(infile.read((char *) &s,sizeof(s)))
add++;
if(add == -1)
return -1; //Database is empty
else
return 1; //Database contains Records
}
int getAddress()
{
ifstream infile(flenme);
if(infile.fail())
errorMsg();
int addr = 0;
student s;
while(infile.read((char *) &s,sizeof(s)))
addr += sizeof(s);
infile.close();
return addr;
}
int Database :: CheckPrimaryKey(int key,tree *t) //Function to Check the Repetition of Primary Key
{
if(key <= 0)
return 1; //Error
if(key == t -> key)
return 1; //Error, Duplicate Primary Key
else if(key < t -> key)
t = t -> left;
else
t = t -> right;
while(t != NULL)
{
if(key == t -> key)
return 1;
else if(key < t -> key)
t = t -> left;
else
t = t -> right;
}
return 0;
}
void Database :: Add(student s,tree *&t)
{
if(t != NULL)
{
int status = CheckPrimaryKey(s.getroll(),t);
if(status)
{
cout << endl << setw(44) << "Invalid Roll Number";
cout << endl << setw(43) << "Please, try again";
return;
}
}
ofstream outfile;
outfile.open(filename,ios::app);
if(outfile.fail())
errorMsg();
outfile.write((char *) &s,sizeof(s));
if(outfile.good())
{
if(s.getroll() > 0)
{
insert(s.getroll(),getAddress(),t),
cout << "\n\n" << setw(42) << "Record Added";
cout << endl << setw(52) << "Press any key to continue...";
}
else
{
cout << endl << setw(44) << "Invalid Roll Number";
cout << endl << setw(43) << "Please, try again";
return;
}
}
else
errorMsg();
outfile.close();
}
void Database :: Search(int roll,tree *&t)
{
int addr = -1;
tree *temp = t;
if(roll == temp -> key)
addr = temp -> address;
else if(roll < temp -> key)
temp = temp -> left;
else
temp = temp -> right;
while(temp != NULL)
{
if(roll == temp -> key)
{
addr = temp -> address;
break;
}
else if(roll < temp -> key)
temp = temp -> left;
else
temp = temp -> right;
}
if(addr == -1)
cout << endl << setw(43) << "Record Not Found";
else
{
ifstream infile(flenme);
if(infile.fail())
errorMsg();
student s;
infile.seekg(addr);
infile.read((char *) &s,sizeof(s));
infile.close();
cout << "\n\n" << setw(47) << "Record Found";
cout << endl << setw(74);
cout << "---------------------------------------------------------------\n";
cout << setw(15) << "Roll" << setw(20) << "Name";
cout << setw(20) << "Faculty" << setw(15) << "Marks" << endl;
cout << setw(74) << "---------------------------------------------------------------\n";
cout << setw(45) << s;
cout << endl << setw(74);
cout << "---------------------------------------------------------------\n";
cout << endl << setw(55) << "Press any key to continue...";
}
}
void Database :: Modify(int roll,tree *&t)
{
int addr = -1;
tree *temp = t;
if(roll == temp -> key)
addr = temp -> address;
else if(roll < temp -> key)
temp = temp -> left;
else
temp = temp -> right;
while(temp != NULL)
{
if(roll == temp -> key)
{
addr = temp -> address;
break;
}
else if(roll < temp -> key)
temp = temp -> left;
else
temp = temp -> right;
}
if(addr == -1)
cout << endl << setw(43) << "Record Not Found";
else
{
fstream file(flenme,ios::in | ios::out);
if(file.fail())
errorMsg();
student s;
file.seekg(addr);
file.read((char *) &s,sizeof(s));
cout << "\n\n" << setw(47) << "Current Record";
cout << endl << setw(74);
cout << "---------------------------------------------------------------\n";
cout << setw(15) << "Roll" << setw(20) << "Name";
cout << setw(20) << "Faculty" << setw(15) << "Marks" << endl;
cout << setw(74) << "---------------------------------------------------------------\n";
cout << setw(45) << s;
cout << endl << setw(74);
cout << "---------------------------------------------------------------\n";
cout << "\n\n" << setw(43) << "Enter New Record\n\n";
file.seekp(0,ios::beg);
int rn = s.getroll();
char nme[20],fact[15];
float mks;
cin.ignore();
cout << endl << setw(32) << "Name : ";
cin.getline(nme,20);
cout << endl << setw(35) << "Faculty : ";
cin >> fact;
cout << endl << setw(33) << "Marks : ";
cin >> mks;
student st(rn,nme,fact,mks);
temp -> key = s.getroll();
file.seekp(addr);
file.write((char *) &st,sizeof(st));
if(file.good())
cout << "\n\n" << setw(50) << "Record Modified Successfully";
else
cout << "\n\n" << setw(42) << "Error : Please try again...";
file.close();
cout << endl << setw(52) << "Press any key to continue...";
}
}
void Database :: Remove(int roll,tree *&t)
{
int addr = -1;
tree *temp = t;
if(roll == temp -> key)
addr = temp -> address;
else if(roll < temp -> key)
temp = temp -> left;
else
temp = temp -> right;
while(temp != NULL)
{
if(roll == temp -> key)
{
addr = temp -> address;
break;
}
else if(roll < temp -> key)
temp = temp -> left;
else
temp = temp -> right;
}
if(addr == -1)
cout << endl << setw(43) << "Record Not Found";
else
{
temp -> key = -1;
fstream file(flenme,ios::in | ios::out);
student s,temp;
file.seekg(addr);
file.read((char *) &s,sizeof(s));
temp = s;
temp.editRoll(-1);
file.seekp(addr);
file.write((char *) &temp,sizeof(temp));
if(file.good())
cout << "\n\n" << setw(50) << "Record Deleted Successfully";
else
cout << "\n\n" << setw(42) << "Error : Please try again...";
file.close();
cout << endl << setw(52) << "Press any key to continue...";
}
}
void Database :: Clear()
{
fstream file(flenme,ios::in | ios::out);
ofstream temp("temp.txt");
if(temp.fail())
{
clrscr();
cout << endl << setw(45) << "Internal Error";
cout << endl << setw(45) << "Settings were not saved";
cout << "\n\n" << setw(42) << "Please try again...";
exit(0);
}
student s;
while(file.read((char *) &s,sizeof(s)))
{
if(s.getroll() != -1)
temp.write((char *) &s,sizeof(s));
}
file.close();
temp.close();
remove(flenme);
rename("temp.txt",flenme);
}
int loadDB(Database &d,tree *&t)
{
d.Clear();
int success = d.createDB();
student s;
t = NULL;
if(success == -1)
return 1;
if(success == 0)
return 0;
int add = 0;
ifstream infile(flenme);
while(infile.read((char *) &s,sizeof(s)))
{
insert(s.getroll(),add,t);
add += sizeof(s);
}
infile.close();
return 1;
}
void DBinfo()
{
cout << endl << setw(42);
cout << "Database Name : " << flenme;
student s;
int total = 0;
ifstream infile(flenme);
while(infile.read((char *) &s,sizeof(s)))
{
if(s.getroll() != -1)
total++;
}
infile.close();
cout << endl << setw(44);
cout << "Total Record(s) : " << total;
}
void Database :: Help()
{
clrscr();
cout << setw(45) << "************\n";
cout << setw(41) << "HELP\n";
cout << setw(46) << "************\n\n";
cout << "\t-->";
cout << "This program is developed, coded and completed as a class Project ";
cout << "on 16th Sharawan 2067 (August 01, 2010).\n";
cout << "\tThis Program is developed using the concept of Data Structure in ";
cout << "C and\nC++ Languages. The concept of Tree is used to increase the ";
cout << "performance of the\nprogram. The Binary Search Tree is created ";
cout << "according to the roll no. of the\nstudents stored in file. The ";
cout << "Database is processed from the Tree.";
cout << "\n\n1. The user can work on multiple number of Database by loading ";
cout << "different \n database using option 1.";
cout << "\n2. Different operations on database can be carried out from option ";
cout << "2 to 7.";
cout << "\n3. You can view the database informations using options 7.";
cout << "\n\n\n\n\n\n\n" << setw(48) << "Press any key to continue...";
}
void Msg()
{
cout << endl << setw(45) << "Load Database First";
cout << endl << setw(50) << "Press any key to continue...";
}
void Menu()
{
clrscr();
cout << "\n\t\t **********************************" << endl;
cout << "\t\t * ---------------------- *" << endl;
cout << "\t\t * DATABASE MANAGEMENT SYSTEM *" << endl;
cout << "\t\t * ---------------------- *" << endl;
cout << "\t\t **********************************" << endl << endl;
cout << "\t ----------------------------------\n\n";
cout << "\t\t 1. Load Database\n" << endl;
cout << "\t\t 2. Add New Data\n" << endl;
cout << "\t\t 3. View All Data\n" << endl;
cout << "\t\t 4. Modify Existing Data\n" << endl;
cout << "\t\t 5. Delete Existing Data\n" << endl;
cout << "\t\t 6. Search\n" << endl;
cout << "\t\t 7. Current Database Information\n" << endl;
cout << "\t\t 8. Help\n" << endl;
cout << "\t\t 0. Exit From Program\n" << endl;
cout << "\t\t ----------------------------------\n\n";
cout << "\t\t\t Enter Choice : ";
}
int main()
{
Database d;
student s;
tree *tr;
int choice,success,rln;
do
{
Menu();
cin >> choice;
switch(choice)
{
case 0:
clrscr();
d.Clear();
cout << "\n\n\n\n\n\n\n\n\n";
cout << setw(52) << "DATABASE MANAGEMENT SYSTEM\n\n";
cout << setw(53) << "A Project on Data Structure\n\n";
cout << setw(45) << "By Ankit Pokhrel";
cout << "\n\n\n\n\n" << setw(50) << "Press any key to halt...";
getch();
return 0;
case 1:
success = loadDB(d,tr);
if(success)
{
cout << endl << endl << setw(53) << "Database Loaded Successfully";
cout << endl << setw(53) << "Press any key to continue...";
}
else
cout << endl << endl << setw(53) << "Press any key to continue...";
break;
case 2:
if(d.isDBloaded())
{
cout << endl << setw(45) << "Enter Informations\n\n";
cin >> s;
d.Add(s,tr);
}
else
Msg();
break;
case 3:
if(d.isDBloaded())
{
cout << endl << setw(74);
cout << "---------------------------------------------------------------\n";
cout << setw(15) << "Roll" << setw(20) << "Name";
cout << setw(20) << "Faculty" << setw(15) << "Marks" << endl;
cout << setw(74) << "---------------------------------------------------------------\n";
inorder(tr);
cout << endl << setw(53) << "Press any key to continue...";
}
else
Msg();
break;
case 4:
if(d.isDBloaded())
{
cout << endl << setw(43) << "Enter Roll No : ";
cin >> rln;
d.Modify(rln,tr);
}
else
Msg();
break;
case 5:
if(d.isDBloaded())
{
cout << endl << setw(43) << "Enter Roll No : ";
cin >> rln;
d.Remove(rln,tr);
}
else
Msg();
break;
case 6:
if(d.isDBloaded())
{
cout << endl << setw(43) << "Enter Roll No : ";
cin >> rln;
d.Search(rln,tr);
}
else
Msg();
break;
case 8:
d.Help();
break;
case 7:
if(d.isDBloaded())
DBinfo();
else
Msg();
break;
default:
cout << endl << setw(53) << "Please Select Appropriate Option";
}
getch();
}while(1);
}
No comments:
Post a Comment