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

Describe entity referential integrity and integrity, Describe entity refere...

Describe entity referential integrity and integrity. Give an example of each. Entity Integrity Rule - If there is a attribute A of relation R is a prime attribute of R then A

Define the concept of design documentation, Design Documentation  The ...

Design Documentation  The Design Document shall be an extension of Requirements Analysis Design. "The Design Document will comprise a revised and much more detailed descrip

Ways to suggest the dba, a)  Suppose we updated the catalog tables in real ...

a)  Suppose we updated the catalog tables in real time, that is, after every update, insert, or delete SQL statement were executed-rather than only running RUNSTATS once every few

Homework, can you resolve this for me please? Database Management Systems ...

can you resolve this for me please? Database Management Systems Homework 1 The following relations are given (primary keys are underlined): PLAY-ACTOR(AId, Name, Nationality, Birt

What database management system, Company XYZ is an advertising company. It...

Company XYZ is an advertising company. It has its own website but the search facilities offered are not reliable. The company is willing to invest to acquire new machines and sof

Working and processing files, 1.  Define each of the following IN YOUR OWN ...

1.  Define each of the following IN YOUR OWN WORDS: (a)   File: (b)   Record: (c)   Field: (d)   Primary Key: (e)   Secondary Key: 2.  A travel agency wants t

Need senior oracle database administrator, Project Description: Oracle C...

Project Description: Oracle Certified Professional with 20 years of practice, Oracle version 6.0.34, 7.3, 8.0, 8i, 9i, 10G, 11G, 12C. Crossplatform migration, Informix, MSSql

Computer, what is object-identity

what is object-identity

Explain an attributes, What are attributes? Give examples. An entity is...

What are attributes? Give examples. An entity is shown by a set of attributes. Attributes are descriptive properties possessed by every member of an entity set. Example: pos

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