programming basics

2603 WordsFeb 2, 201411 Pages
CHAPTER 7: DATA MODELING USING THE ENTITY-RELATIONSHIP (ER) MODEL Answers to Selected Exercises 7.16 - Consider the following set of requirements for a UNIVERSITY database that is used to keep track of students' transcripts. This is similar but not identical to the database shown in Figure 1.2: (a) The university keeps track of each student's name, student number, social security number, current address and phone, permanent address and phone, birthdate, sex, class (freshman, sophomore, ..., graduate), major department, minor department (if any), and degree program (B.A., B.S., ..., Ph.D.). Some user applications need to refer to the city, state, and zip of the student's permanent address, and to the student's last name. Both…show more content…
7.20 - No solution provided. 7.21 - Additional information: - There are 435 congresspersons in the U.S. House of Representatives. - States have between one (AK, DE, MT, ND, SD, VT, and WY) and 52 (CA) representatives. - M represents number of bills during the 2-year session. The resulting ER Diagram is shown in Figure A. 7.22 - A database is being constructed to keep track of the teams and games of a sports league. A team has a number of players, not all of whom participate in each game. It is desired to keep track of the players participating in each game for each team, the positions they played in that game, and the result of the game. Try to design an ER schema diagram for this application, stating any assumptions you make. Choose your favorite sport (soccer, football, baseball ...). Answer: The following design may be used for a baseball league. Here, we assumed that each game in the schedule is identified by a unique Game#, and a game is also identified uniquely by the combination of Date, starting Time, and Field where it is played. The Performance attribute of PARTICIPATE is used to store information on the individual performance of each player in a game. This attribute can be designed to keep the information needed for statistics, and may be quite complex. One possible design for the Performance attribute may be the following (using the notation of Figure 7.8): Performance( {Hitting(AtBat#, Inning#, HitType, Runs,
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