1. CIS 336 CIS336 Week 2 iLab 2 Devry University
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General Questions - General General Questions
Lab two introduces the next step in creating a data model, the Entity Relationship Diagram (ERD). You
will be given a business scenario for a company named Clapham Specialty Store, which is a small
specialist grocery and delicatessen. The business specifications will outline a number of things about
the business, some of which will apply directly to the database you are being asked to model. There is a
table which lists the entities (tables) that will be needed for the database and related attributes
(columns) for each entity. There is also a column that lists specific information about the entity that
will be helpful in determining its relationship to other entities within the model. Be sure to include the
minimum and maximum occurrences of each relationship (cardinality) and to supply a name to the
relationship that will work in both directions. If there is not a single word that will apply, then supply a
separate name for each direction of the relationship. Narrative/Case Study TheClapham Specialty Store
is a small, specialist grocery and delicatessen. A new owner, John Balfour, who would like to expand
the store and improve its profits, has recently purchased the store. The store sells general groceries,
wines and liquors, and has a small deli counter. The store is open from 5:00 a.m. to 12:00 midnight.
Many of the customers are repeat customers who come in to buy products they forgot from their
regular grocery shopping expedition at the supermarket. The store sells about 3,000 different products
ranging from toilet cleaner to 2 oz. jars of caviar, and champagne to liverwurst. Each product is
displayed on a shelf on one side or the other of the aisle. The products arrive and their details (cost,
quantity, SKU number, package size, purchase date) are recorded in the back room before they are
displayed. The new owner wants to know which products the store sells most of and which are the most
profitable. The following is some general information about the company and its current processes. The
store has 3 cash registers. Between 3 and 7 employees will work at any given time, depending on the
time of day and how busy they are. An employee logs in to the register at the start of a shift and logs
out at the end. The name, address, Social Security number and other information is recorded for every
employee. All employees are paid weekly against an hourly rate which varies depending on their job
description. Each sale is identified by a Receipt No. and a timestamp (date and time) and consists of
sale items with a quantity and price recorded for each product. As a convenience for known customers,
they offer a local delivery service. Deliveries are only made to customers who are registered at the
store; walk-ins must record their name, address, and phone number before a delivery can be made to
them. John can find the cost of the goods from the accounts system. What John would like to have is a
point of sale system (POS) that records what has been sold to whom, by whom, for how much, and
when. Also, he needs to be able to record the delivery trips that are made, who makes the delivery, how
long the delivery takes, and the amount of the sale. There is concern at this point that the cost of
delivering the sales to customers is not worth the return on investment. Requirements: You have been
asked to develop a logical data model for Clapham Specialty Store based on the information given to
you by John and his staff. Through analysis of the nouns and verbs in the case study above, you have
accumulated the following entity, attribute, and relationship information shown in the table below. The
attribute list may not be complete. If you determine that additional attributes are needed to better define
an entity then you should add them. Entities Attributes and Relationships for Clapham Store: Entity
Attributes Relationships Employee ID Number, Last Name, First Name, Phone Number, Employee
Type ID An Employee can belong to any one of the three job categories, but can belong to one and

2. only one of the three. Employees have names and other contact information. Employee Type Type ID,
Description, Hourly Pay Rate An employee can be either a clerk, delivery person, or a supervisor.
Register Log Register Log Number, Register Number, Log In Time, Log Out Time, Employee ID Sales
are made using a register and can be tracked by the register log number. An employee must log into the
register before he/she can use it and must log out when finished with a shift at that register. An
employee may use more than one register during a period of work. Register Register Number, Register
Location Description, Register Serial Number The store has 3 registers: One located at the back of the
store and two located at the front of the store; one on the left and one on the right of the entrance.
Deliveries Delivery Number, Employee ID, Sales Receipt Number, Time the Employee Left and
Returned Relates to both the employee and the sale entities. This entity will help track deliveries. An
employee can make many deliveries but a sale is delivered by one and only one employee. Location
Location ID, Aisle, Side, Shelf Relates to product and identifies one or more areas of the store where
products are displayed. Product Product ID, Name, Package Size, Cost, Quantity on Hand (QOH), Last
Purchased Date, Reorder Minimum Identifies the products the store sells. One or more products can be
sold per sale. The quantity on hand allows John to determine his inventory levels. The reorder
minimum can be used to determine when the inventory level has reached a reorder point. Sale Receipt
Number, Sales Amount, Sale Date- Time A sale is identified by a single receipt. Sales are: made to one
or more Customers but only one customer at a time. made by one or more Register Clerks but only one
clerk per sale. recorded on one or more Registers but only one register per sale. delivered by one or
more delivery persons but no one sale can be delivered by more than one delivery person. Sold Items
Receipt Number, Product ID, Item Price, Quantity Sold Sale Item is part of sale and records product
sold per sale. Sale item must be able to associate multiple products sold on a single sales receipt.
Customer Customer Number, First Name, Last Name, Address, Phone Number A customer can be
associated with multiple sales, but any one sale is to one and only one customer. A sale can occur
without a customer registering in the system. Using MS Visio, develop an ERD that meets the
following guidelines: Draw the entities with their attributes. Indicate the relationships between the
entities using Crow's Foot notation. You will need to determine the cardinality and optionality for each
direction of the relationships. Some of the Foreign Key relationships are identified in the graph above
but not all. Be sure you identify and account for all Foreign Key relationships. Add a name (in both
directions) to the relationships. Remember, if you can verbalize the relationship in both directions then
you probably have a valid relationship. Deliverables The deliverable for this lab will be your completed
ERD as a single MS Word document using copy/paste from the MS Visio application and named
"lab2_solutions_yourname". L A B S T E P S STEP 1: Drawing entities and attributes Be sure to
include all of the entities that have been defined. You need to include at least the primary and foreign
key attributes where applicable in your diagram. STEP 2: Indication of all relationships Be sure that
you link all entities based on PK to FK relationships. There may be a case where you need to identify a
combination PK and if so make sure that all of the relationships involved are defined. Be sure that you
have set your Visio editor to show Crow's Foot notation. Also, be sure that you are defining the correct
cardinality for the relationships. STEP 3: Naming of relationships Do not accept the default naming
convention for your relationships in all cases. There may be some relationships where this is
applicable, but in most cases you will want to explicitly name the relationship. Be sure that you have
provided a verb phrase for both directions in the relationship. This is the end of lab #2