The following tables form part of a database held in a relational DBMS:- Hotel (hotelNo, hotelName, city) Room (roomNo, hotelNo, type, price) Booking (hotelNo, guestNo, dateFrom, dateTo, roomNo) Guest...

The following tables form part of a database held in a relational DBMS:-
Hotel (hotelNo, hotelName, city)
Room (roomNo, hotelNo, type, price)
Booking (hotelNo, guestNo, dateFrom, dateTo, roomNo)
Guest (guestNo, guestName, guestAddress)
where Hotel contains hotel details and hotelNo is the primary key;
Room contains room details for each hotel and (roomNo, hotelNo) forms
the primary key;
Booking contains details of the bookings and (hotelNo, guestNo,dateFrom) forms the primary key; and Guest contains guest details and guestNo is the primary key.

b.Explain how the entity and referential integrity rules apply to these relations.


c. Briefly discuss the main reasons for introducing the concepts of superclasses and subclasses into an ER model?