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

Assignment Help:

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))


Related Discussions:- Write a query to find name from the relational algebra

Domains, Every simple attribute of an entity type have a possible set of va...

Every simple attribute of an entity type have a possible set of values that can be attached to it. This is known as the domain of an attribute. An attribute cannot have a value out

Insert into command, INSERT INTO command : Values can be inserted fo...

INSERT INTO command : Values can be inserted for all columns or for the selected columns Values can be given by sub query. In place of values parameter substitution

The locking protocol, The Locking Protocol: To manage concurrency related ...

The Locking Protocol: To manage concurrency related problems we use locking. A lock is mainly a variable that is associated with a data item in the database. A lock can be located

Er diatgrams, Ask q“A database will be made to store information about pati...

Ask q“A database will be made to store information about patients in a hospital. On arrival, each patient’s personal details (name, address, and telephone number) are recorded wher

Prepare heart failure registry database, Prepare Heart Failure Registry dat...

Prepare Heart Failure Registry database How are you today? Please I would like you to design a Heart Failure registry where doctors will log in to enter information about their

Secondary indexes, Secondary Indexes Let consider the student database ...

Secondary Indexes Let consider the student database and its clustering index and primary (only one will be applicable at a time). Now consider the state when the database is to

Locks, Locks: Serialisabilty is just a test whether a given interleaved sch...

Locks: Serialisabilty is just a test whether a given interleaved schedule is ok or has a concurrency related trouble. Though, it does not make sure that the interleaved concurrent

Describe the different raid levels, Describe the different RAID levels.  Di...

Describe the different RAID levels.  Discuss the choices of the different RAID levels for different applications.          Ans:   There are several combinations of these approa

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd