WGU D426: OBJECTIVE ASSESSMENT
EXAM LATEST 2026/2027 WITH ACTUAL
QUESTIONS AND CORRECT VERIFIED
ANSWERS ALREADY GRADED A+
Question 1
A database contains information about students enrolled at a university. Which statement BEST
describes a relational database?
A. A collection of unstructured files stored in folders
B. A database that organizes data into related tables
C. A database that can only store numerical data
D. A database that does not allow relationships between records
Correct Answer: B
Rationale:
A relational database organizes data into tables consisting of rows and columns. Relationships
between tables are established using keys such as primary keys and foreign keys. The relational
model is designed to reduce unnecessary duplication while maintaining relationships between
related data.
Question 2
Which term describes a characteristic or property of an entity?
A. Relationship
B. Attribute
C. Tuple
D. Constraint
Correct Answer: B
Rationale:
An attribute describes a property of an entity. For example, a STUDENT entity might have
attributes such as StudentID, FirstName, LastName, and DateOfBirth.
,Question 3
Which BEST describes a primary key?
A. A field that can contain duplicate values
B. A field used only for sorting records
C. A field or combination of fields that uniquely identifies a row
D. A field that must always contain text
Correct Answer: C
Rationale:
A primary key uniquely identifies each record in a table. Primary-key values cannot be
duplicated, and the primary key cannot contain NULL values.
Question 4
A CUSTOMER table contains:
CustomerID, CustomerName, Email, Phone
Which would be the BEST primary key?
A. CustomerName
B. Phone
C. CustomerID
D. Email
Correct Answer: C
Rationale:
CustomerID is specifically designed to uniquely identify each customer. Names, phone numbers,
and email addresses may potentially change or may not be guaranteed to be unique.
Question 5
What is the primary purpose of a foreign key?
A. To encrypt a table
B. To establish a relationship between tables
,C. To automatically sort records
D. To eliminate all NULL values
Correct Answer: B
Rationale:
A foreign key is an attribute or group of attributes in one table that references a key—normally
the primary key—in another table. It helps establish and enforce relationships between tables.
Question 6
A company has departments and employees. Each employee works in one department, while
each department can have many employees. What type of relationship exists between
Department and Employee?
A. One-to-one
B. One-to-many
C. Many-to-many
D. Many-to-one only
Correct Answer: B
Rationale:
One department can have many employees, while each employee belongs to one department.
Therefore, from Department to Employee, the relationship is one-to-many.
Question 7
Students can enroll in many courses, and each course can have many students. What type of
relationship is this?
A. One-to-one
B. One-to-many
C. Many-to-many
D. Zero-to-one
Correct Answer: C
Rationale:
A student can take multiple courses, and a course can have multiple students. This creates a
many-to-many relationship.
, In a relational database, this is normally resolved using an associative/junction table, such as:
ENROLLMENT(StudentID, CourseID)
Question 8
Which SQL statement creates a table?
A. MAKE TABLE
B. CREATE TABLE
C. NEW TABLE
D. BUILD TABLE
Correct Answer: B
Rationale:
CREATE TABLE is a SQL Data Definition Language (DDL) statement used to create the structure
of a table.
Question 9
Which SQL statement is used to add a new row to a table?
A. UPDATE
B. INSERT
C. ALTER
D. CREATE
Correct Answer: B
Rationale:
INSERT adds new records to an existing table.
Example:
INSERT INTO Student
(StudentID, StudentName)
VALUES
(101, 'John Smith');
EXAM LATEST 2026/2027 WITH ACTUAL
QUESTIONS AND CORRECT VERIFIED
ANSWERS ALREADY GRADED A+
Question 1
A database contains information about students enrolled at a university. Which statement BEST
describes a relational database?
A. A collection of unstructured files stored in folders
B. A database that organizes data into related tables
C. A database that can only store numerical data
D. A database that does not allow relationships between records
Correct Answer: B
Rationale:
A relational database organizes data into tables consisting of rows and columns. Relationships
between tables are established using keys such as primary keys and foreign keys. The relational
model is designed to reduce unnecessary duplication while maintaining relationships between
related data.
Question 2
Which term describes a characteristic or property of an entity?
A. Relationship
B. Attribute
C. Tuple
D. Constraint
Correct Answer: B
Rationale:
An attribute describes a property of an entity. For example, a STUDENT entity might have
attributes such as StudentID, FirstName, LastName, and DateOfBirth.
,Question 3
Which BEST describes a primary key?
A. A field that can contain duplicate values
B. A field used only for sorting records
C. A field or combination of fields that uniquely identifies a row
D. A field that must always contain text
Correct Answer: C
Rationale:
A primary key uniquely identifies each record in a table. Primary-key values cannot be
duplicated, and the primary key cannot contain NULL values.
Question 4
A CUSTOMER table contains:
CustomerID, CustomerName, Email, Phone
Which would be the BEST primary key?
A. CustomerName
B. Phone
C. CustomerID
D. Email
Correct Answer: C
Rationale:
CustomerID is specifically designed to uniquely identify each customer. Names, phone numbers,
and email addresses may potentially change or may not be guaranteed to be unique.
Question 5
What is the primary purpose of a foreign key?
A. To encrypt a table
B. To establish a relationship between tables
,C. To automatically sort records
D. To eliminate all NULL values
Correct Answer: B
Rationale:
A foreign key is an attribute or group of attributes in one table that references a key—normally
the primary key—in another table. It helps establish and enforce relationships between tables.
Question 6
A company has departments and employees. Each employee works in one department, while
each department can have many employees. What type of relationship exists between
Department and Employee?
A. One-to-one
B. One-to-many
C. Many-to-many
D. Many-to-one only
Correct Answer: B
Rationale:
One department can have many employees, while each employee belongs to one department.
Therefore, from Department to Employee, the relationship is one-to-many.
Question 7
Students can enroll in many courses, and each course can have many students. What type of
relationship is this?
A. One-to-one
B. One-to-many
C. Many-to-many
D. Zero-to-one
Correct Answer: C
Rationale:
A student can take multiple courses, and a course can have multiple students. This creates a
many-to-many relationship.
, In a relational database, this is normally resolved using an associative/junction table, such as:
ENROLLMENT(StudentID, CourseID)
Question 8
Which SQL statement creates a table?
A. MAKE TABLE
B. CREATE TABLE
C. NEW TABLE
D. BUILD TABLE
Correct Answer: B
Rationale:
CREATE TABLE is a SQL Data Definition Language (DDL) statement used to create the structure
of a table.
Question 9
Which SQL statement is used to add a new row to a table?
A. UPDATE
B. INSERT
C. ALTER
D. CREATE
Correct Answer: B
Rationale:
INSERT adds new records to an existing table.
Example:
INSERT INTO Student
(StudentID, StudentName)
VALUES
(101, 'John Smith');
