BSc (Hons) Web Technologies. BSc (Hons) Business Information System. Examinations for 2016 Semester 2. Resit Examination for BIS/15A/FT & BIS/15B/FT

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1 BSc (Hons) Web Technologies BSc (Hons) Business Information System Cohort: BWT/16A/FT Examinations for 2016 Semester 2 Resit Examination for BIS/15A/FT & BIS/15B/FT MODULE: DATABASE MANAGEMENT SYSTEM MODULE CODE: DBT1101 Duration: 2 Hours 30 Minutes Instructions to Candidates: 1. Attempt ANY FOUR questions. 2. Questions may be answered in any order but your answers must show the question number clearly. 3. Always start a new question on a fresh page. 4. Total marks This Exam paper contains 5 questions and 7 pages including this page. DO NOT TURN PAGE OVER UNTIL INSTRUCTED DATABASE MANAGEMENT SYSTEM (DBT1101) SITE/Dec 2016 Sem 2 Page 1 of 7

2 QUESTION 1 [25 Marks] (a) What is a metadata? (b) What is a business rule, and what is its purpose into data model components? (c) Contrast the following terms with an appropriate example: (i) stored attribute v/s derived attribute (iii) (iv) (v) entity type v/s entity instance strong entity type v/s weak entity type simple attribute v/s composite attribute unary relationship v/s binary relationship (5 X 2 marks) (d) Constraints are rules that restrict the data values that you can enter into a field in a database table. Briefly describe the following constraint with appropriate example for each: (i) Check Constraint Not Null Constraint (iii) Unique Constraint (3 X 2 marks) (e) Explain the following database languages and show appropriate example for each: (i) DDL DML (4 marks) DATABASE MANAGEMENT SYSTEM (DBT1101) SITE/Dec 2016 Sem 2 Page 2 of 7

3 QUESTION 2 [25 Marks] (a) What is normalization? (b) Briefly discuss the concept of transitive dependency. (c) Referring to the table structure shown below: (i) Give an example of an insertion anomaly Write the relational schema, draw its dependency diagram and identify all dependencies (including all partial and transitive dependencies). Where: ManNo. Means Manager Number Man Name means Manager Name Emp# means Employee Number (10 marks) Store Code StoreName Region Code RegionDes cription ManNo ManName Emp# EmpLName EmpFName EmpDOB 1 Access Junction 2 West 8 Johnsson 6 Renselaer Cary 25-Dec-65 1 Access Junction 2 West 8 Johnsson 20 Mckee Robert 06-Mar-70 1 Access Junction 2 West 8 Johnsson 8 Johnsson Elizabeth 10-Sep-68 2 Database Corner 2 West 12 Washington 2 Ratula Nancy 09-Feb-69 2 Database Corner 2 West 12 Washington 9 Eindsmar Jack 19-Apr-55 2 Database Corner 2 West 12 Washington 12 Washington Alan 08-Sep-74 3 Tuple Charge 1 East 7 Ogallo 21 Baumann Jennifer 11-Dec-74 3 Tuple Charge 1 East 7 Ogallo 13 Smith Peter 25-Aug-64 3 Tuple Charge 1 East 7 Ogallo 11 Broderick Tom 21-Oct-72 3 Tuple Charge 1 East 7 Ogallo 5 Smith Robert 23-Nov-59 3 Tuple Charge 1 East 7 Ogallo 7 Ogallo Roberto 31-Jul-62 4 Attribute Alley 2 West 3 Greenboro 17 Grimaldo Jeanine 12-Nov-70 4 Attribute Alley 2 West 3 Greenboro 18 Rosenberg Andrew 24-Jan-71 4 Attribute Alley 2 West 3 Greenboro 19 Rosten Peter 03-Oct-68 4 Attribute Alley 2 West 3 Greenboro 3 Greenboro Lottie 02-Oct-61 (d) Draw an ERD from the tables obtained through the Normalisation Process above. (9 marks) DATABASE MANAGEMENT SYSTEM (DBT1101) SITE/Dec 2016 Sem 2 Page 3 of 7

4 QUESTION 3 [25 Marks] (a) The term integrity refers to the accuracy or correctness of the data in the database. Define the following terms: (i) Entity Integrity Referential Integrity (2 x 2 ½ marks) (b) The Defense Research Establishment (DRE) regularly performs secret space missions to other planets. Now they need a database to administrate the space mission. The database contains data about a number of planets, each of which has a unique number, a name, and a distance from the Earth. There are also data about DRE's spaceships, each of which have a unique number, date constructed and a unique name. DRE has made a number of missions to different planets. Each such mission has a unique number, a name, a start date (when they left the Earth) and a return date (when they returned to Earth). In each mission, there is only one spaceship involved. During a mission, a particular spaceship may visit one or more planets and the date landed and date left the planet during a mission should also be recorded in the database. DRE also wants to keep data about astronauts each of which has a unique number, last name and first name, who goes on a mission. A mission can have more than one astronaut, but only one astronaut will lead the mission. (i) Draw an ERD for the scenario given above. (10 marks) Convert the logical ER diagram produced in (a) above into its physical design. You have to choose an appropriate Primary Key for each table identified in the scenario and underline it to differentiate it with other non key attributes. You also have to show any identified Foreign Key in the physical designed. (10 marks) Page 4 of 7

5 QUESTION 4 [25 Marks] This Question is based on the data shown in Appendix. Given this information, express the following queries in Relational Algebra. (a) Draw an Entity-Relationship Diagram for the relational schema given in the Appendix. Show all the entities, relationships, relationship names, and attributes and also underline the primary key for each entity. (4 marks) (b) Explain the type of query the following statements in relational algebra is performing, and give the expected values of the table RESULT when using the initial values of the tables provided in the appendix. (i) RESTRICT WARD WHERE WARDNAME = Surgical GIVING T1 JOIN T1 AND REQUEST OVER WARD# GIVING T2 RESTRICT T2 WHERE MEALDATE = 26-MAR-2012 GIVING T3 JOIN T3 AND MEAL_REQUEST OVER REQUEST# GIVING T4 PROJECT T4 OVER FOODTYPE, MEALTYPE, QUANTITY GIVING RESULT (5 Marks) RESTRICT WARD WHERE WARDNAME = SURGICAL GIVING T1 JOIN T1 AND REQUEST OVER WARD# GIVING T2 RESTRICT T2 WHERE MEALDATE = 26/03/12 GIVING T3 JOIN T3 AND MEAL_REQUEST OVER REQUEST# GIVING T4 PROJECT T4 OVER FOODTYPE GIVING T5 RESTRICT WARD WHERE WARDNAME = CARDIAC GIVING T6 JOIN T6 AND REQUEST OVER WARD# GIVING T7 RESTRICT T7 WHERE MEALDATE = 26/03/12 GIVING T8 JOIN T8 AND MEAL_REQUEST OVER REQUEST# GIVING T9 PROJECT T9 OVER FOODTYPE GIVING T10 T5 MINUS T10 GIVING RESULT (c) (5 Marks) Express the following queries using relational algebra first and then in SQL: (i) Get the name of those wards who requested Weetabix for breakfast for the 26 th March (6 Marks) Get the name of those wards that did not request Weetabix for breakfast for the 26 th March (5 Marks) Page 5 of 7

6 QUESTION 5 [25 Marks] This Question is based on the data shown in Appendix. Write the following queries using SQL. (a) Write the SQL code that will create the FOOD table and make the FOODTYPE the Primary key of the table. The data type for each attribute should be as specified in the sample values given in the Appendix. (b) Create the WARD table without the Primary Key constraint. (c) After creating the WARD table in section (b) above,write SQL code to make the WARD# the Primary key constraint for the WARD table. (d) Write SQL code to create the REQUEST table. Your code should have the REQUEST# as the PRIMARY KEY and the WARD# as the FOREIGN KEY constraint. (e) Assuming the MEAL_REQUEST table has already been created without the PRIMARY KEY AND FOREIGN KEY constraints. Write code to make the REQUEST#, FOODTYPE and MEALTYPE to be the COMPOSITE PRIMARY KEY of the table. (f) Assuming that all the tables have been created as given in the relational schema in the Appendix, write SQL code to make the following changes in the structure of the tables. (i) Create a constraint for the MealType in the Meal_Request table so that this column will accept only the following values: Breakfast, Lunch and Dinner Make the Ward Name of each Ward to be unique, so that no two Wards would have the same Name. (g) Write SQL code to insert the first row in the Request Table assuming that the ward table has already been populated. (h) Write SQL code to change the number of bed from 25 to 20 for the Surgical ward (i) Write SQL code to display all the food type and their quantities requested by the Cardiac ward for dinner requested on the 25th March (4 marks) Page 6 of 7

7 APPENDIX You are given the following tables which represent the meal Request for a hospital. Table: REQUEST Request# RequestDate MealDate Ward# Requested By /03/ /03/ J. Mc Smith /03/ /03/ M. Munroe Table: WARD Ward# WardName No_of_Bed 10 Cardiac Surgical Orthopaedic 20 Table: MEAL_REQUEST Request# FoodType MealType Quantity 6435 Weetabix Breakfast Round of Toast Breakfast Grapefruit Breakfast Shepherd s Pie Lunch Ham Sandwich Lunch Ham Sandwich Dinner Round of Toast Dinner Corn Flakes Breakfast Round of Toast Breakfast Tuna Sandwich Lunch Shepherd Pie Lunch Ham Sandwich Dinner Fish and Chips Dinner 9 Table: FOOD FoodType UnitCost Weetabix $0.50 Round of Toast $1.00 Grapefruit $0.80 Shepherd s Pie $2.50 Ham Sandwich $1.20 Corn Flakes $0.50 Tuna Sandwich $1.00 Fish and Chips $1.80 ***END OF QUESTION PAPER*** Page 7 of 7