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Cardinalities_practice_-_solutions

# Cardinalities_practice_-_solutions - Cardinalities Practice...

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Cardinalities Practice – Solutions SEMANTIC PROBLEMS 1. ALL RESTAURANTS IN SAN FRANCISCO ALL RESTAURANTS IN CALIFORNIA (1,1) (0,1) 2. SFSU STUDENT ALL SFSU EMAIL ADDRESS (1,1) (0,1) By policy, each SFSU student gets one and only one SFSU email account. However, there are many SFSU email addresses (for example, faculty and staff) that are not related to students. 3. ACCOUNTING MAJORS FINANCE MAJORS (0,1) (0,1) 4. ALL PEOPLE IN CALIFORNIA CURRENT MARRIAGE LICENSES (0,1) (1,N) Not every Californian is married (minimum cardinality on PEOPLE IN CALIFORNIA = 0). A divorce, annulment, or death nullifies a current marriage license, and polygamy is illegal, so one person can have at most only one current marriage license (maximum cardinality on PEOPLE IN CALIFORNIA = 1). Each marriage license has exactly two people on it (maximum cardinality on CURRENT MARRIAGE LICENSE = N). Note: If you put the maximum cardinality for CURRENT MARRIAGE LICENSE as 2, that would be wrong! Your only choices are 1 or N for the maximum cardinality.

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5. MOVIE MPAA RATING (1,1) (1,N)
ENTITY TABLES 1. BICYCLE PARTS FINISHED BICYCLES (1,N) (1,N) 2. INSTRUMENTS BANDS (0,N) (1,N) 3. US CURRENCY CURRENCY VALUE (1,1) (0,N) No single piece of currency has a face value of \$2.25 or \$3.00 (minimum cardinality on CURRENCY VALUE = 0). 4. MNFG EXPENDITURES COST TYPE (1,N) (0,N) A manufacturing expenditure must be either a direct cost or an indirect cost; therefore, the minimum cardinality on MNFG EXPENDITURES is one. However, a cost may be direct and fixed, direct and variable, indirect and fixed, or indirect and variable (though also possibly none of those if it’s a mixed cost), so therefore the maximum cardinality on manufacturing expenditures is many. There are no preventive costs listed, and nor are there detective costs listed. Therefore, the minimum cardinality on COST TYPE is zero. RELATIONSHIP TABLES

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1. SWEET AND SOUR DISHES RESTAURANT (1,N) (1,N) 2. STUDENT DORMITORY (0,1) (1,N) Andrea Smith does not live in a dorm. Therefore, the STUDENT minimum cardinality is zero. 3. ALPHABETIC CODES NUMERIC CODES (1,N) (0,N) 4. TEXTBOOK ISBN (1,1) (1,1) Solutions to Romney and Steinbart Problems Problem 15.6 – I start with the left-hand entity’s participation cardinalities, then do the right-hand entity. a. An appliance store: one customer can buy many appliances on one invoice and pay in installments with no down payment (0,N). A person may pay for several invoices with one check (1,N).
b. A car dealership: a customer may buy several cars at one time (1,N). Each car is tracked separately, so a car may not yet be sold, but it can only be sold once (0,1). c.

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Cardinalities_practice_-_solutions - Cardinalities Practice...

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