What is a recursive relationship, Database Management System


(a) Can a set of data requirements be correctly modelled by two or more different ER diagrams? Explain your answer. You may use a small example, if you think it will help your explanation.

(b) What is a recursive relationship? Give an example of a many to many recursive relationship.

This question refers to the Appendix where the relational schema for an online DVD rental system is defined.

(c) Express the following queries using relational algebra:

(i) Find all DVD titles with their certificate being ‘15' and their type name being ‘Drama'

(ii) Find names of all members and the titles of DVDs, which they have rented between 1st

May 2007 and 31st
May 2007

(iii) Find names of all the members who have rented any DVD with type name ‘Comedy' but not any DVD with Type name ‘Action'

Posted Date: 11/14/2013 6:23:56 AM | Location : United States

Related Discussions:- What is a recursive relationship, Assignment Help, Ask Question on What is a recursive relationship, Get Answer, Expert's Help, What is a recursive relationship Discussions

Write discussion on What is a recursive relationship
Your posts are moderated
Related Questions
Question : (a) Differentiate between database integrity and database security (b) Database security involves measures to avoid loss of privacy and loss of confidentiality. D

How does Tuple-oriented relational calculus vary from domain-oriented relational calculus? The tuple-oriented calculus uses a tuple variables i.e., variable whose only allowed

Accessing information about permissions to all users- Object level permissions: With the use of data dictionary you can see the permissions to user. Let us get the table name fro

What do you understand by a view? What does WITH CHECK OPTION clause for a view do? - A view is a virtual table which comprises fields from one or more real tables. - It is


Performance of Various Concurrency Control Mechanisms

Create an index for the table Client, field CLIENT_NO of Q ? Command:   CREATE INDEX client_client_no ON client(client_no);

Explain the function of input controls. Identify four types of input control and explain the function of each. Provide an example of a data integrity error that could occur i

What is Nested Trigger? A trigger can also having INSERT, UPDATE and DELETE logic within itself, so when the trigger is fired because of data modification it can also cause ano

Give an example of enforcement in Typing. You can understand the idea of enforcement as it makes sure objects of dissimilar classes may not be interchanged as below:  Exampl