WGU C792 Task 2 ERD Reflection Actual Exam
2026/2027 | Performance Assessment with Detailed
Rationales | Pass Guaranteed – A+ Graded
Section 1: Entity-Relationship Modeling & Cardinality (12 Questions)
Q1: A university wants to track which professors advise which graduate students. Each
professor can advise multiple students, but each student has exactly one primary
advisor. What is the correct cardinality between Professor and Student?
A. One-to-one, because each student needs focused guidance from a single mentor
B. One-to-many from Professor to Student, with the foreign key placed in the Student
table [CORRECT]
C. Many-to-many, since professors often collaborate and students may switch advisors
D. One-to-many from Student to Professor, with the foreign key placed in the Professor
table
Correct Answer: B
Rationale: The best answer is B. This choice is correct because in relational database
design we ensure that the "many" side of a one-to-many relationship carries the foreign
key. Since one professor can advise many students, the Student table gets the
ProfessorID foreign key. What you want to remember for your ERD reflection is that
cardinality direction matters—you always place the foreign key on the side that can have
multiple instances.
,Q2: In a hospital database, a Patient can have multiple Appointments, but each
Appointment belongs to exactly one Patient. Additionally, each Appointment is
scheduled with exactly one Doctor, though a Doctor can have many Appointments. How
many tables are needed at minimum, and what relationships exist?
A. Two tables (Patient and Appointment) with a one-to-many relationship, since Doctor
is just an attribute of Appointment
B. Three tables (Patient, Appointment, Doctor) with one-to-many from Patient to
Appointment and one-to-many from Doctor to Appointment [CORRECT]
C. Three tables with many-to-many between Patient and Doctor, using Appointment as a
bridge table
D. Four tables, because Appointment needs its own separate bridge table between
Patient and Doctor
Correct Answer: B
Rationale: The best answer is B. This choice is correct because in relational database
design we model each independent entity as its own table. Patient and Doctor are both
independent entities, and Appointment is a dependent entity that connects them
through two separate one-to-many relationships. What you want to remember for your
ERD reflection is that when an entity naturally belongs to two parent entities, it carries
foreign keys to both rather than creating an unnecessary associative entity.
Q3: A music streaming service needs to model the relationship between Artists and
Songs. An Artist can create many Songs, and a Song can feature multiple Artists
(collaborations). What is the correct implementation?
,A. A one-to-many from Artist to Song, storing multiple ArtistIDs as a comma-separated
list in the Song table
B. A many-to-many relationship implemented with an associative (junction) table such
as SongArtist [CORRECT]
C. A one-to-many from Song to Artist, since each song is the primary focus and artists
are secondary
D. A recursive relationship on the Artist table, since collaborations are just artists
working with themselves
Correct Answer: B
Rationale: The best answer is B. This choice is correct because in relational database
design we never store multiple values in a single attribute—that violates first normal
form. A many-to-many relationship always requires an associative table when both
sides can have multiple instances. What you want to remember for your ERD reflection
is that comma-separated lists might seem convenient but they destroy your ability to
query, enforce integrity, and normalize your data properly.
Q4: Using Crow's Foot notation, you see a line connecting Customer and Order with a
single vertical bar on the Customer side and a crow's foot with a circle on the Order
side. What does this symbol combination mean?
A. One Customer must have at least one Order, and each Order must belong to exactly
one Customer
B. One Customer may have zero or many Orders, and each Order must belong to exactly
one Customer [CORRECT]
, C. One Customer may have zero or one Order, and each Order may belong to zero or one
Customer
D. One Customer must have exactly one Order, and each Order must belong to exactly
one Customer
Correct Answer: B
Rationale: The best answer is B. This choice is correct because in Crow's Foot notation,
the single bar means "exactly one" (mandatory participation), the crow's foot means
"many," and the circle means "zero" (optional). So the combination of crow's foot plus
circle on the Order side reads as "zero or many." What you want to remember for your
ERD reflection is that you read the symbol closest to the entity—circle means optional,
bar means mandatory, and the crow's foot means multiple.
Q5: A company database tracks Departments and Employees. Each Department must
have at least one Employee (the department head), and each Employee must belong to
exactly one Department. What Crow's Foot notation symbols appear on the Employee
side of this relationship?
A. A crow's foot with a circle, indicating zero or many employees per department
B. A single vertical bar, indicating exactly one employee per department
C. A crow's foot with a vertical bar, indicating one or many employees per department
[CORRECT]
D. Two vertical bars, indicating exactly one and only one employee per department
Correct Answer: C
2026/2027 | Performance Assessment with Detailed
Rationales | Pass Guaranteed – A+ Graded
Section 1: Entity-Relationship Modeling & Cardinality (12 Questions)
Q1: A university wants to track which professors advise which graduate students. Each
professor can advise multiple students, but each student has exactly one primary
advisor. What is the correct cardinality between Professor and Student?
A. One-to-one, because each student needs focused guidance from a single mentor
B. One-to-many from Professor to Student, with the foreign key placed in the Student
table [CORRECT]
C. Many-to-many, since professors often collaborate and students may switch advisors
D. One-to-many from Student to Professor, with the foreign key placed in the Professor
table
Correct Answer: B
Rationale: The best answer is B. This choice is correct because in relational database
design we ensure that the "many" side of a one-to-many relationship carries the foreign
key. Since one professor can advise many students, the Student table gets the
ProfessorID foreign key. What you want to remember for your ERD reflection is that
cardinality direction matters—you always place the foreign key on the side that can have
multiple instances.
,Q2: In a hospital database, a Patient can have multiple Appointments, but each
Appointment belongs to exactly one Patient. Additionally, each Appointment is
scheduled with exactly one Doctor, though a Doctor can have many Appointments. How
many tables are needed at minimum, and what relationships exist?
A. Two tables (Patient and Appointment) with a one-to-many relationship, since Doctor
is just an attribute of Appointment
B. Three tables (Patient, Appointment, Doctor) with one-to-many from Patient to
Appointment and one-to-many from Doctor to Appointment [CORRECT]
C. Three tables with many-to-many between Patient and Doctor, using Appointment as a
bridge table
D. Four tables, because Appointment needs its own separate bridge table between
Patient and Doctor
Correct Answer: B
Rationale: The best answer is B. This choice is correct because in relational database
design we model each independent entity as its own table. Patient and Doctor are both
independent entities, and Appointment is a dependent entity that connects them
through two separate one-to-many relationships. What you want to remember for your
ERD reflection is that when an entity naturally belongs to two parent entities, it carries
foreign keys to both rather than creating an unnecessary associative entity.
Q3: A music streaming service needs to model the relationship between Artists and
Songs. An Artist can create many Songs, and a Song can feature multiple Artists
(collaborations). What is the correct implementation?
,A. A one-to-many from Artist to Song, storing multiple ArtistIDs as a comma-separated
list in the Song table
B. A many-to-many relationship implemented with an associative (junction) table such
as SongArtist [CORRECT]
C. A one-to-many from Song to Artist, since each song is the primary focus and artists
are secondary
D. A recursive relationship on the Artist table, since collaborations are just artists
working with themselves
Correct Answer: B
Rationale: The best answer is B. This choice is correct because in relational database
design we never store multiple values in a single attribute—that violates first normal
form. A many-to-many relationship always requires an associative table when both
sides can have multiple instances. What you want to remember for your ERD reflection
is that comma-separated lists might seem convenient but they destroy your ability to
query, enforce integrity, and normalize your data properly.
Q4: Using Crow's Foot notation, you see a line connecting Customer and Order with a
single vertical bar on the Customer side and a crow's foot with a circle on the Order
side. What does this symbol combination mean?
A. One Customer must have at least one Order, and each Order must belong to exactly
one Customer
B. One Customer may have zero or many Orders, and each Order must belong to exactly
one Customer [CORRECT]
, C. One Customer may have zero or one Order, and each Order may belong to zero or one
Customer
D. One Customer must have exactly one Order, and each Order must belong to exactly
one Customer
Correct Answer: B
Rationale: The best answer is B. This choice is correct because in Crow's Foot notation,
the single bar means "exactly one" (mandatory participation), the crow's foot means
"many," and the circle means "zero" (optional). So the combination of crow's foot plus
circle on the Order side reads as "zero or many." What you want to remember for your
ERD reflection is that you read the symbol closest to the entity—circle means optional,
bar means mandatory, and the crow's foot means multiple.
Q5: A company database tracks Departments and Employees. Each Department must
have at least one Employee (the department head), and each Employee must belong to
exactly one Department. What Crow's Foot notation symbols appear on the Employee
side of this relationship?
A. A crow's foot with a circle, indicating zero or many employees per department
B. A single vertical bar, indicating exactly one employee per department
C. A crow's foot with a vertical bar, indicating one or many employees per department
[CORRECT]
D. Two vertical bars, indicating exactly one and only one employee per department
Correct Answer: C
