Question-29
DBMS
A relational schema for a train reservation database is given below. Passenger (pid, pname, age)
Reservation (pid, class, tid)
Table: Passenger
pid | pname | age |
---|---|---|
0 | Sachin | 65 |
1 | Rahul | 66 |
2 | Sourav | 67 |
3 | Anil | 69 |
Table : Reservation
pid | class | tid |
---|---|---|
0 | AC | 8200 |
1 | AC | 8201 |
2 | SC | 8201 |
5 | AC | 8203 |
1 | SC | 8204 |
3 | AC | 8202 |
What pids are returned by the following SQL query for the above instance of the tables?
SLECT pid
FROM Reservation ,
WHERE class "AC" AND
EXISTS (
SELECT *
FROM Passenger
WHERE age > 65
AND Passenger.pid = Reservation.pid
)
Answer