a) True
b) False
2) You can only create relationships to a Supertype, not to a Subtype. True or False?
a) True
b) False
3) When creating entities you must follow these rules: (Choose Two)
(Choose all correct answers)
a) Name them in Plural
b) Name them in Singular
c) Exclude Attributes
d) Include Attributes
4) All ER diagrams must have one of each of the following: (Choose two)
(Choose all correct answers)
a) One or more Entities
b) Relationships between entities
c) Arcs
d) At least one supertype and subtype
5) Business rules are important to data modelers. True or False?
a) True
b) False
6) Modeling historical data can produce a unique identifier that always excludes dates. True or False?
a) True
b) False
7) Which of the following scenarios should be modeled
so that historical data is kept? (Choose two)
(Choose all correct answers)
a) Baby and Age
b) Customer and Payments
c) Teacher and Age
d) Customer and Orders
8) All relationships participating in an arc must be mandatory. True or False?
a) True
b) False
9) Primary UIDs are:
a) Something that each Entity should have, but is not
mandatory
b) Useful as an alternative means of identifying instances
of an entity, independent of their datatype
c) Mandatory in data modeling
d) Always comprised of numbers
10) Arcs are Mandatory in Data modeling. All ERD's must have at least one Arc. True or False?
a) True
b) False
11) Which of the following is NOT a relationship type?
a) Some to None
b) One to One
c) One to Many
d) Many to Many
12) Which of the following would best be represented by an arc?
a) Teacher (Female, Bob)
b) Delivery Address (Home, Office)
c) Parent (Girl, Bob)
d) Student (Grade A student, Average Student)
13) Which of the following would be good as a Unique Identifier for its Entity? (Choose Three)
(Choose all correct answers)
a) Personal Identification number for Person
b) Vehicle Registration Number for Car
c) ISBN Number for Book
d) Date of birth for Baby
14) recursive relationship must Mandatory at
both ends. True or False?
a) True
b) False
15) Which of the following statements about relationships are true? (Choose Two)
(Choose all correct answers)
a) They become foreign keys in the database.
b) They must be mandatory to be created in the database.
c) They can be either mandatory or optional.
d) They must exist between two different Entities.
16) Volatile entities have special requirements and need special attention when you are doing data modelling. True or False?
a) True (*)
b) False
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Suggested Answers
1) b
2) b
3) b, d
4) a, b
5) a
6) b
7) b, d
8) b
9) a
10) b
11) a
12) b
13) a, b, c
14) b
15) a, c
16) a
