1. a) 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.

Identify the foreign keys in this schema. Explain how the entity and referential integrity rules apply to these relations.

b) Describe the relations that would be produced by the following relational algebra operations (use the schema from question a):

1. PhotelNo (sprice > 50 (Room) )

c) PhotelName (Hotel Hotel.hotelNo = Room.hotelNo (sprice > 50 (Room)) )

6. PguestName, hotelNo (Booking Booking.guestNo = Guest.guestNo Guest)

PhotelNo (scity = London(Hotel))