Databases Assignment 1

CBEC 1404

Certificate in Technology

Databases 1

CBEC 1404 – Databases I (Introduction to Databases) Assignment 1 – Conceptual Databases Design Task 1: Conceptual Database Design Given the following entity-relationship diagram, reproduce the database schema to reflect the removal of the many-many relationship.

Task 1: Solution

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©Dumitru Afanasiev 2010

CBEC 1404


Databases 1

Task 2: Conceptual Database Design A publishing company produces computing books on various subjects. The books are written by authors who specialize in one particular subject. The company employs editors who, not necessarily being specialists in a particular area, each take sole responsibility for editing one or more publications. A publication covers essentially one of the specialist subjects and is normally written by a single author. When writing a particular book, each author works with one editor, but may submit another work for publication to be supervised by other editors. To improve their competitiveness, the company tries to employ a variety of authors, more than one author being a specialist in a particular subject. Carry out the following: Prepare a conceptual model, in the form of an entity-relationship diagram, for these business requirements. Your submission should include a “relationship matrix” Task 2: Solution

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CBEC 1404


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Task 3: Conceptual Database Design Assume you have the following database schema: Note: Key attributes are underlined. GIRLSCOUTS(ScoutID, GSName, Troop#, Address, City, Phone, email, DOB) TROOPS(Troop#, LeaderName, LeaderPhone, AgeGroup) ORDERS(OrderID, ScoutID, CustomerID, DeliveryDate) BISCUITS(OrderID, ScoutID, Biscuit, BoxedSold) CUSTOMERS(CustomerID, CustName, CustAddress) Assumptions: • • • • • •

Biscuit is the type of Biscuit bought (for example, Ginger Snaps). All troops have at least one Girl Scout. It’s possible that a Girl Scout makes no biscuit sales. You only keep track of customers who have bought biscuits. A customer can place more than one order. The orderID refers to the order ID of a particular a girl scout. For example, girl scouts 23 and 56 can both have an order ID 1.

Carry out the following: • • • •

Reproduce a “relationship matrix” to illustrate each of the relationship identified. Provide a brief description of each of the relationship identified in your “relationship matrix”. Reproduce the corresponding fully attributed “key–based” entityrelationship diagram. Provide a brief description of the cardinally illustrated in your entityrelationship diagram.

Note: Do not add any new fields to the tables. Task 3: Solution

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Databases Assignment 1

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