THE RELATIONAL DATABASE MODEL: ADDITIONAL CONCEPTS - Fundamentals of Database Management Systems - page 141

(d) PRODUCT relation

Product Number Unit

Number Name Price

16386 Wrench 12.95

19440 Hammer 17.50

21765 Drill 32.99

24013 Saw 26.25

26722 Pliers 11.50

(e) SALES relation

Salesperson Produc t

Numbe r Numbe r Quantity

137 19440 473

137 24013 170

137 26722 688

186 16386 1745

186 19440 2529

186 21765 1962

186 24013 3071

204 21765 809

204 26722 734

361 16386 3729

361 21765 3110

361 26722 2738

(f) OFFICE relation

Office
Number Telephone Size (sq. ft.)

1253 901-555-4276 120

1227 901-555-0364 100

F IGURE 6.1 (Continued)
General Hardware Company relational
database

1284 901-555-7335 120

1209 901-555-3108 95

Assume that the General Hardware Co. has two levels of sales managers,
resulting in a three-level hierarchy. That is, each salesperson reports to a sales
manager (who is himself a salesperson) and each sales manager reports to one of
several chief sales managers (who is herself a salesperson). Figure 6.3 shows two
levels of sales managers plus the salespersons who report to them. For example,
salespersons 142, 323, and 411 all report to salesperson (and sales manager) 137.
Salespersons 137 and 439, both of whom are sales managers, report to salesperson
186 who is a chief sales manager. As you go upward in the hierarchy, each
salesperson is associated with exactly one other salesperson. As you go downward
in the hierarchy from any salesperson/sales manager, each salesperson/sales manager