Web-DSS-Chapter-03

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72 CHAPTER 3 ■ Entity-Relationship Modelinga. For tax purposes, the Coca Cola Companyextends the data kept for each employee toinclude additional information about theirdependents. This information consists of eachdependent’s name, birth date, and age.b. The company has decided to record informationabout its suppliers and the rawmaterial(s) supplied by them. The followinginformation is recorded for each supplier: thesupplier identification number, the address,and the name of the contact person. The rawmaterial information consists of the raw materialidentification number and the material’sname.c. The company keeps a fleet of vehicles to facilitatethe distribution of the products to thecustomers. Each vehicle has an identificationnumber, model, and capacity.It should also be noted that employees use rawmaterials to produce one or more final products,which are delivered to the customer. A suppliersupplies many raw materials, but a particular rawmaterial is purchased from only one supplier. Itis not necessary to include all the attributes andcardinalities from the previous question. Just besure to include the entities to demonstrate therelationships and attributes for the new entities.4. Again consider the database in Hands-On Exercise2. The Coca Cola Company has a few plantsthat are distributed throughout Georgia. For eachplant, the following information is stored in thedatabase: a plant identification number, theaddress, and the X and Y coordinates of the plantlocation. Note that the inventory level, inventorycapacity, and quantity produced of a particularproduct differ by plant.The systems of relationships that exist are asfollows. A plant may have one or more employees,and an employee works in exactly one plant.Additionally, a plant produces one or more products,and a product may be produced in one ormore plants. Also, an employee may contributeto one or more products, and a product is producedby exactly one employee. It is not necessaryto include all the attributes and cardinalitiesfrom the previous question. Just be sure to includethe entities to demonstrate the relationshipsand attributes for the new entities.5. Major airline companies that provide passengerservices in Taiwan are UniAir, TransAsia Airways,Far Eastern Transport, and Great ChinaAirlines. Taiwan’s Federal Aviation Administration(TFAA) maintains a database with informationabout all the airlines. This information ismade accessible to all airlines in Taiwan with theintention of helping the companies assess theircompetitive position in the domestic market. Theinformation consists of the following:a. Each airline has an identification number, aname and address, a contact person’s name,and a telephone number.b. Each aircraft has an aircraft identificationnumber, a capacity, and a model.c. Each employee has an employee identificationnumber, a name, an address, a birth date, agender, a position within the company, and aqualification.d. Each route has a route identification number,an origin, a destination, a classification (domesticor international route), a distance ofthe route, and a price charged per passenger.e. Each airline records information about itsbuy/sell transactions. (For example, selling anairplane ticket is a sell transaction; paying formaintenance is a buy transaction.) Each transactionhas a transaction identification number,a date, a description, and an amount ofmoney paid/received.The above information is related as follows. Eachemployee works for exactly one airline. Airlinesassign different aircraft on different routes basedon the availability. Furthermore, each airlinemakes one or more transactions; however, eachtransaction is associated with exactly one airline.Make the necessary assumptions about the otherrelationships and draw an E-R diagram.6. Consider the database described in Hands-OnExercise 5. Each airline owns different aircraftmodels, each with a different capacity. Dependingon the length of the route and flight classification(domestic or international) the aircraft areassigned to different routes. The relationshipbetween the airlines, aircraft, and routes is aternary relationship. Each flight carries a numberof passengers, has a particular time length (whichdepends on the distance of the route and themodel of the aircraft), and has a departure andarrival time. Draw the E-R diagram for thisdatabase.
SECTION 3.22 ■ Exercises 737. “Electronic commerce” is one of the most commonterms in the business world. It is the buyingand selling of goods and services on the Internet.One of the most popular products in e-commerce,as it is more commonly known, is the compactdisc. This exercise describes the database of a CDwarehouse.The company’s customers and employeesaccess the database. Assume that customers haveaccess to a company’s <strong>Web</strong> site and that they areable to open an account by providing their socialsecurity number, name, address, and music preferences.For each employee, the following informationis recorded: an employee identificationnumber, a name, an address, a birth date, and thetitle of the position within the company.The products for the CD warehouse are thealbums. The database records the following informationabout each album: an album identificationnumber, the name, the group name, themusical category, the name of the vocalist, thenames of the other band members, and the numberof CDs in stock. The database also keeps thefollowing information about suppliers: a supplieridentification number, the address, the name ofthe company, and the name of the contactperson.An album may be bought by one or morecustomers, and one customer may buy one ormore albums. Additionally, an employee maymonitor one or more albums; however, an albumis monitored by exactly one employee. Suppliersmay provide one or more albums; however, analbum is supplied by exactly one supplier. Usingthe above information, draw an E-R diagram forthe CD warehouse database. Identify the relationshipcardinalities and the key attribute of eachentity.8. One of the three-star hotels in the Miami area isin the process of updating its database. The hotelhas various room types on each of its floors. Therooms may be regular, deluxe, or a suite and eachcan be either a single, double, or triple. The suiteshave ocean views and are bigger than the regularrooms. The deluxe rooms are as big as suites, butthey do not have an ocean view. All the roomshave air conditioning. Most of the rooms arenon-smoking, but the hotel offers some smokingrooms as well. Each floor has a different numberof a particular room type. The price of each roomdiffers by the size of the room, the view, and theroom’s location (first floor, second floor, etc.).The customers are charged on a per-daybasis. The number of days is computed based onthe check-in time and the check-out time. Thefollowing details are stored for each customer:name, address, check-in date, check-out date,payment method, and final bill amount. In additionto the room charges, there may be extra fees,such as telephone usage, fax services, extra beds,and room service. For this application, we assumethat a room can be booked by more thanone customer as long as there is no overlap andthat a customer can be assigned to any availableroom. Draw an E-R diagram for the hotel databaseand state any assumptions made in order todevelop a complete diagram.9. The Newark divisional office of the Life InsuranceCorporation of America stores all the necessaryinformation about its policyholders in adatabase. A policyholder pays a premium untilthe maturity of the policy or until his or herdeath, at which time the sum assured and thebonus are paid to the beneficiary. The premiumto be paid is determined based on the age of theperson proposed and the term of the policy. TheNewark division records the following informationabout each policyholder: social securitynumber, name, address, date of birth, maturityamount, and annual premium.The corporation has divided its Newarkdivision into 15 zones for its convenience. Foreach zone, they store the Zone ID and the location.Each zone also has a manager. Every zonehas a number of agents allotted, typically rangingfrom 10 to 20 and every agent must procure aminimum of 10 customers. Each policyholder ina particular zone is assigned to only one agentaffiliated with that zone; this agent puts forth theterms of the policy. Additionally, an agent in aparticular zone can serve multiple policyholders.Make assumptions for the remaining relationshipsand draw an E-R diagram for the corporation’sdatabase.10. Ford distribution centers provide automotiveparts to authorized dealers. The dealers thendistribute the parts to customers throughoutNorth America. Ford is under pressure to provideexcellent customer service at a minimumcost. Maintaining a well-organized database of
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