Page 189 - C++

(c) Find the output of the following C++ code considering that the binary file CLIENT.DAT exists on the hard
disk with a data of 1000 clients: (1)

class CLIENT

{

int Ccode; char CName[20];

public:

void Register(); void Display():

};

void main()

{

fstream CFile;
CFile.open("CLIENT.DAT",ios::binary|ios::in);

CLIENT C;
CFile.read((char*)&C, sizeof(C));

cout<<"Rec: "<<CFile.tellg()/sizeof (C)<<endl;
CFile.read((char*)&C, sizeof(C));

CFile.read((char*)&C, sizeof(C)):

cout<<"Rec:"<<CFile.tellg()/sizeof(C)<<endl;

CFile.close():

}

Ans.

Output

Rec: 1
Rec: 3
OR

(c) Which file stream is required for tellg() function ? (1)

Ans. fstream.h or ifstream.h

Q5 (a) What do you understand by Primary Key & Candidate Keys? (2)

Ans. An attribute or set attributes which are used to identify a tuple uniquely is known as Primary Key. If a
table has more than one such attributes which identify a tuple uniquely than all such attributes are known as
Candidate Keys.