Write a program in C++ to implement sequential file for students' database and perform following operations on it i) Create Database ii) Display Database iii) Add a record iv) Delete a record v) Modify a record.

       FILE OPERATIONS IN CPP USING SWITCH CASE.

   

PROGRAM FOR FILE OPERATIONS.

• Write a program in C++ to implement sequential file for students' database and perform following operations on it 

          i) Create Database. 
          ii) Display Database.  
          iii) Add a record.  
          iv) Delete a record.  
          v) Modify a record. 

#include<fstream.h>
#include<iostream.h>
#include<string.h>
#include<conio.h>
#include<process.h>
using namespace std;
class file
{
private:
 int roll;
 float age;
 char name[100];
public:
 void input();
 void show();
 char *getn()
 {
  return name;
 }
};file fileobj;
 
void file::input()
{
 cout<<"Enter the roll, Age and name :";
 cin>>roll>>age;
 gets(name);
}
void file::show()
{
 cout<<"Roll==> "<<roll<<endl;
 cout<<"Age ==> "<<age<<endl;
 cout<<"Name==> "<<name<<endl;
}
void Create();
void Add();
void Display();
void DisplayP();
void Modify();
void Delete();
 
fstream fil;
int main()
{
 int opt;
 while(1)
 {
  clrscr();
  cout<<"1.Create Data File"<<endl;
  cout<<"2.Add New Record in Data File"<<endl;
  cout<<"3.Display Record From Data File"<<endl;
  cout<<"4.Display Particular Record From Data File"<<endl;
  cout<<"5.Modify Paricular Record From Data File"<<endl;
  cout<<"6.Delete Particular Record From Data File"<<endl;
  cout<<"7.Exit From the Program"<<endl;
  cout<<"Enter your Option : "<<endl;
  cin>>opt;
  switch(opt)
  {
   case 1:
   {
    Create();
    cout<<"Display Main Menu"<<endl;
    getch();
    break;
   }
   case 2:
   {
    Add();
    cout<<"Display Main Menu"<<endl;
    getch();
    break;
   }
   case 3:
   {
    Display();
    cout<<"Display Main Menu"<<endl;
    getch();
    break;
   }
   case 4:
   {
    DisplayP();
    cout<<"Display Main Menu"<<endl;
    getch();
    break;
   }
   case 5:
   {
    Modify();
    cout<<"Display Main Menu"<<endl;
    getch();
    break;
   }
   case 6:
   {
    Delete();
    cout<<"Display Main Menu"<<endl;
    getch();
    break;
   }
   case 7:
   {
    exit(0);
   }
   default:
   {
    cout<<"Wrong Choice....Press Key For View the Main Menu";
    getch();
    clrscr();
   }
  }
 }
}
 
void Create()  //Function to Create Data File
{
 char ch='y';
 fil.open("binary.dat",ios::out| ios::binary);
 while(ch=='y' || ch =='Y')
 {
  fileobj.input();
  fil.write((char*)&fileobj, sizeof(fileobj));
  cout<<"Want to Continue.....";
  cin>>ch;
 }
 fil.close();
}
 
void Add()              //Function to Add New Record in Data File
{
 char ch='y';
 fil.open("binary.dat",ios::app| ios::binary);
 while(ch=='y' || ch =='Y')
 {
  fileobj.input();
  fil.write((char*)&fileobj, sizeof(fileobj));
  cout<<"Want to Continue.....";
  cin>>ch;
 }
 fil.close();
}
 
void Display()  //Function to Display All Record from Data File
{
 fil.open("binary.dat",ios::in| ios::binary);
 if(!fil)
 {
  cout<<"File not Found";
  exit(0);
 }
 else
 {
  fil.read((char*)&fileobj, sizeof(fileobj));
  while(!fil.eof())
  {
   fileobj.show();
   cout<<"Press Any Key....For Next Record"<<endl;
   getch();
   fil.read((char*)&fileobj, sizeof(fileobj));
  }
 }
 fil.close();
}
 
void DisplayP()  //Function to Display particular Record from Data File
{
 char n[100];
 cout<<"Enter Name that should be searched:";
 gets(n);
 fil.open("binary.dat",ios::in| ios::binary);
 if(!fil)
 {
  cout<<"File not Found";
  exit(0);
 }
 else
 {
  fil.read((char*)&fileobj, sizeof(fileobj));
  while(!fil.eof())
  {
   if(strcmp(n,fileobj.getn())==0)
   {
    fileobj.show();
    cout<<"Press Any Key...."<<endl;
    getch();
   }
   else
   {
     cout<<"Press Any Key....For Search"<<endl;
     getch();
   }
   fil.read((char*)&fileobj, sizeof(fileobj));
  }
 }
 fil.close();
}
void Modify()  //Function to Modify Particular Record from Data File
{
 char n[100];
 cout<<"Enter Name that should be searched:";
 gets(n);
 fil.open("binary.dat",ios::in| ios::out|ios::binary);
 if(!fil)
 {
  cout<<"File not Found";
  exit(0);
 }
 else
 {
  fil.read((char*)&fileobj, sizeof(fileobj));
  while(!fil.eof())
  {
   if(strcmp(n,fileobj.getn())==0)
   {
    fil.seekg(0,ios::cur);
    cout<<"Enter New Record.."<<endl;
    fileobj.input();
    fil.seekp(fil.tellg() - sizeof(fileobj));
    fil.write((char*)&fileobj, sizeof(fileobj));
   }
   else
   {
     cout<<"Press Any Key....For Search"<<endl;
     getch();
   }
   fil.read((char*)&fileobj, sizeof(fileobj));
  }
 }
 fil.close();
}
 
void Delete()  //Function to Delete Particular Record from Data File
{
 char n[100];
 cout<<"Enter Name that should be Deleted :";
 gets(n);
 ofstream o;
 o.open("new.dat",ios::out|ios::binary);
 fil.open("binary.dat",ios::in| ios::binary);
 if(!fil)
 {
  cout<<"File not Found";
  exit(0);
 }
 else
 {
  fil.read((char*)&fileobj, sizeof(fileobj));
  while(!fil.eof())
  {
   if(strcmp(n,fileobj.getn())!=0)
   {
    o.write((char*)&fileobj, sizeof(fileobj));
   }
   else
   {
     cout<<"Press Any Key....For Search"<<endl;
     getch();
   }
   fil.read((char*)&fileobj, sizeof(fileobj));
  }
 }
 o.close();
 fil.close();
 remove("binary.dat");
 rename("new.dat", "binary.dat");
}