COB 204 FINAL (JOHN GUO) EXAM QUESTIONS WITH CORRECT ANSWERS

COB 204 FINAL (JOHN GUO) EXAM
QUESTIONS WITH CORRECT
ANSWERS



\.Amber needed to improve the efficiency of her eBay shop, so she designed a
relational database. She made sure to include ____________ to figure out how
many orders are associated with each customer.
A. A primary key
B. A foreign key
C. A crow's Foot Cardinality as the maximum cardinality
D. Cardinalities

E. A Cardinality as the minimum cardinality - ANSWERS✔-D. Cardinalities


\.In Figure 1, a(n) ________ symbol in the minimum position on the line symbol
means that an instance of that type is mandatory.
A. oval
B. arrow
C. bar
D. crow's foot

E. Cardinality - ANSWERS✔-C. Bar


\.In Figure 1, the square symbols each represent a(n) _____.

,A. cardinality
B. entity
C. relationship
D. table

E. attribute - ANSWERS✔-B. entity


\.In Figure 1, the __________ consist of the small vertical bar, small oval, and
crow's foot symbols.
A. cardinalities
B. entities
C. relationships
D. tables

E. attributes - ANSWERS✔-A. Cardinalities


\.In a database built based on the ERD shown in Figure 2, the logical association
between Major and Student is created when the __________ of Major is posted
into Student where it plays the part of a(n)__________.
A. primary key, foreign key
B. primary key, non-key attribute
C. foreign key, primary key

D. foreign key, non-key attribute - ANSWERS✔-C. foreign key, primary key

, \.When querying a database built based on the ERD shown in Figure 2, you want
the output that shows how many students there are for one major. Which of the
following clauses should be added to the query to produce the desired output?
SELECT MajorCode, COUNT(SID)
FROM Student
__________ ;
A. WHERE SID IS NOT NULL
B. GROUP BY MajorCode
C. AS "Total Number of Students"
D. ORDER BY SID

E. ORDER BY MajorCode - ANSWERS✔-B. GROUP BY MajorCode


\.When querying a database built based on the ERD shown in Figure 2, which of
the following options should be entered into the blank to correctly complete this
FROM clause?FROM Major JOIN Student ON Major.MajorCode = __________
A. Product.SaleProdID
B. Student.SID
C. Major.SID
D. Student.MajorCode

E. Student.Decl_Date - ANSWERS✔-D. Student.MajorCode


\.When querying a database built based on the ERD shown in Figure 2, if we know
that the students are from various countries including the USA, which of the
following statements about the query output will be TRUE when we run the
following query?