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

When are two schedules said to be view equivalent, When are two schedules s...

When are two schedules said to be view equivalent?     Ans: Two schedules that is denoted as S and S' are said to be view equivalent if the subsequent three conditions are met

Define physical and logical data independence, Define physical and logical ...

Define physical and logical data independence. How does this architecture help in achieving these? Data independence entails that change in one view must not need a change in t

Explain the attribute inheritance, Explain the Attribute inheritance An...

Explain the Attribute inheritance Ans: Throughout the rendering of the objects in a view, attribute sets of objects higher in the view hierarchy are inherited via objects below

Define the traditional system analysis and design, Define the Traditional S...

Define the Traditional System Analysis and Design Traditional System Analysis and Design (SAD) have three basic life cycle models. A typical software lifecycle consists of the

Determine the advantage of object-orientation, Determine the advantage of o...

Determine the advantage of object-orientation Finally, object-orientation has advantage of continuity throughout analysis, persistent representation and design implementation.

How to insert data in your table from another table, How to Insert data in ...

How to Insert data in your table from another table? insert into e.g, To insert tuples from employee into N_emp created above, use following statement Insert into N_emp

By which techniquestransaction processing is associated, By which technique...

By which techniquesTransaction processing is associated? Transaction processing is associated by producing detail, summary, or exception reports and recording a business activi

What are the objectives of query processing, What are the objectives of que...

What are the objectives of query processing?       Ans: The objectives of query processing is to transform a query written in a high level language into a accurate and efficien

What is the main goal of raid technology, What is the main goal of RAID tec...

What is the main goal of RAID technology? Describe the levels 1 through 5. RAID stands for Redundant Array of Inexpensive (or sometimes "Independent")Disks. RAID is a met

What is ocr, What is OCR? OCR (Optical Character Recognition) is a tech...

What is OCR? OCR (Optical Character Recognition) is a technology that enables you to change different types of machine-readable documents, like scanned paper documents, PDF fil

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