Consider the following schema:
Book(ISBN,Title,Publisher,PublicationDate)
Author(AName,Birthdate)
Publisher(Pname,Address)
Wrote(ISBN,AName) // which author wrote which book
Use the relational algebra to express the following queries:
(a) Find all book titles published by Acme Publishers
(b) Find all authors of the book with ISBN 0444455551
(c) Find all authors who published at least one book with Acme Publishers
(d) Find all authors who never published a book with Acme Publishers.
Solution:
(a) 
(b) 
(c) 
(d) 
Computer Science & Information Technology
You might also like to view...
As shown in the accompanying figure, a closed envelope icon appears for a read message.
Answer the following statement true (T) or false (F)
Computer Science & Information Technology
A thesaurus provides:
A) Words with similar meanings B) Reading level of the document C) Correct word usage
Computer Science & Information Technology
Recursively displays a base 10 number in a given base Pre : decimalNumber is positive; base > 10
What will be an ideal response?
Computer Science & Information Technology
A single _____ port can connect up to 127 devices and is hot swappable.
What will be an ideal response?
Computer Science & Information Technology