Integrity of a database enforced by integrity rules, Database Management System

Assignment Help:

Question:

This Question refers to the database schema given in the Appendix.

(a) The integrity of a database is enforced by integrity rules. Discuss what should happen on an attempt to delete the target of a foreign key reference (for example, to delete a lecturer in the LECTURER table who lectures at least one unit listed in the TIMETABLE table)? Your discussion should describe the three possible techniques which can be used to deal with the problem, and provide one example for each technique by using the above tables.

(b) Using the database schema, express the following queries in SQL:

(i) Create the TIMETABLE table including the primary and foreign key constraints in the code. Make any assumption you want to make.

(ii) Insert the first row in the TIMETABLE table and make any assumption.

(iii) Modify the code value to Workshop for the above record created assuming that the rest of the values have already been created.

(iv) Find the numbers of students who have achieved one or more final grade greater than 14.

(v) Find the student number, unit number and final grade for those students attending units run by the departments named ‘computing' or
‘accountancy'.


Related Discussions:- Integrity of a database enforced by integrity rules

Data Minnning, Can i get help with weka software

Can i get help with weka software

List and describe the different types of indexes, Question 1 Indexes are o...

Question 1 Indexes are ocasionally defines on a single field of a file called an indexing field. List and describe the different types of indexes Question 2 Consider a book i

Explain the b+ tree, Explain the B + tree? B + tree is a type of tre...

Explain the B + tree? B + tree is a type of tree which denotes sorted data in a way that permits for efficient insertion, retrieval and removal of records, each of which is

What is difference among mysql_connect and mysql_pconnect, What is differen...

What is difference among mysql_connect and mysql_pconnect? Mysql_connect() opens a new connection to the database while mysql_pconnect() opens persistent connection to the data

What is a data dictionary, What is a data dictionary?  A data dictionar...

What is a data dictionary?  A data dictionary is a data structure which keeps Meta data about the structure of the database i.e.  the schema of the database.

Explain data independence, Explain data independence ? Data independenc...

Explain data independence ? Data independence is the capacity to modify the schema at one stage of a database system without having to change the schema at the further level.

Sources of utilities for a dbms, There are three main sources of utilities ...

There are three main sources of utilities and applications for a DBMS: a. Vendor applications and utilities are given for working with or maintaining the database, and generally

Fragmentation, let us consider a table having 2200 records and the fixed si...

let us consider a table having 2200 records and the fixed size of the table to be considered as 25.then how many numbers of table is requredto perform horizontal fragmentation

Equijoin, When every condition appears with equality condition (=) only. c)...

When every condition appears with equality condition (=) only. c)   Natural join (denoted by R*S) When two join attributes have the similar name in both relations. (Tha

Production management, create an er diagram for production management in fi...

create an er diagram for production management in film industry

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