Write a query to find name from the relational algebra, Database Management System

Consider the relations
City (city_name, state)
Hotel (name, address)
City_hotel (hotel_name, city_name, owner)

Answer the following queries in relational algebra
(i) Find out the names and address of hotels in Agra.
(ii) List the names of cities that have no hotel.
(iii) List the names of the hotels owned through ‘Taj Group'.

Ans: (i) Π name, address ( σ city_name= ‘Agra' (Hotelname=city_name City_hotel))
(ii) Π city_name (City) - Π city_name(City_hotel)
(iii) Π hotel_name ( σ owner='Taj Group' (City_hotel))

Posted Date: 5/11/2013 4:02:50 AM | Location : United States







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