1|Page
WGU D427 OBJECTIVE ASSESSMENT FINAL EXAM
AND PRACTICE EXAM LATEST 2026-2027 ACTUAL
EXAM WITH COMPLETE QUESTIONS AND CORRECT
DETAILED ANSWERS (100% VERIFIED ANSWERS)
|ALREADY GRADED A+||PROFESSOR VERIFIED
|BRANDNEW!!
Which table has a composite foreign key? ```plaintext 1.
DepartmentStaff table 2. EmployeeManager table 3.
HealthPlan table ``` - ANSWER-HealthPlan table
What is referential integrity in relational databases? -
ANSWER-Referential integrity is a rule that requires
foreign key values to be either fully NULL or match some
primary key value.
,2|Page
What are the four ways to violate referential integrity? -
ANSWER-1. A primary key is updated. 2. A foreign key is
updated. 3. A row containing a primary key is deleted. 4. A
row containing a foreign key is inserted.
Refer to the Department and Employee tables. Identify the
foreign key value that violates referential integrity.
```plaintext Department Code Name Manager 44
Engineering 2538 82 Sales 6381 12 Marketing 6381 99
Technical Support 3829 Employee ID Name Salary 2538
Lisa Ellison 45000 5384 Sam Snead 30500 6381 Maria
Rodriguez 92300 ``` - ANSWER-Manager 3829 in the
Technical Support department violates referential integrity
because there is no employee with ID 3829.
,3|Page
How can referential integrity violations be corrected? -
ANSWER-Violations can be corrected manually or
automatically using SQL constraints such as RESTRICT,
SET NULL, SET DEFAULT, or CASCADE.
What does the RESTRICT constraint do in SQL? -
ANSWER-The RESTRICT constraint rejects any insert,
update, or delete operation that violates referential
integrity.
What does the SET NULL constraint do in SQL? -
ANSWER-The SET NULL constraint sets invalid foreign
keys to NULL when the referenced primary key is deleted
or updated.
, 4|Page
What does the SET DEFAULT constraint do in SQL? -
ANSWER-The SET DEFAULT constraint sets invalid
foreign keys to their default value when the referenced
primary key is deleted or updated.
What does the CASCADE constraint do in SQL? -
ANSWER-The CASCADE constraint propagates primary
key changes to foreign keys. If a primary key is deleted,
matching foreign keys are also deleted. If a primary key is
updated, matching foreign keys are updated to the new
value.
What do the ON DELETE and ON UPDATE clauses
specify in a FOREIGN KEY constraint? - ANSWER-The
ON DELETE and ON UPDATE clauses specify the actions
WGU D427 OBJECTIVE ASSESSMENT FINAL EXAM
AND PRACTICE EXAM LATEST 2026-2027 ACTUAL
EXAM WITH COMPLETE QUESTIONS AND CORRECT
DETAILED ANSWERS (100% VERIFIED ANSWERS)
|ALREADY GRADED A+||PROFESSOR VERIFIED
|BRANDNEW!!
Which table has a composite foreign key? ```plaintext 1.
DepartmentStaff table 2. EmployeeManager table 3.
HealthPlan table ``` - ANSWER-HealthPlan table
What is referential integrity in relational databases? -
ANSWER-Referential integrity is a rule that requires
foreign key values to be either fully NULL or match some
primary key value.
,2|Page
What are the four ways to violate referential integrity? -
ANSWER-1. A primary key is updated. 2. A foreign key is
updated. 3. A row containing a primary key is deleted. 4. A
row containing a foreign key is inserted.
Refer to the Department and Employee tables. Identify the
foreign key value that violates referential integrity.
```plaintext Department Code Name Manager 44
Engineering 2538 82 Sales 6381 12 Marketing 6381 99
Technical Support 3829 Employee ID Name Salary 2538
Lisa Ellison 45000 5384 Sam Snead 30500 6381 Maria
Rodriguez 92300 ``` - ANSWER-Manager 3829 in the
Technical Support department violates referential integrity
because there is no employee with ID 3829.
,3|Page
How can referential integrity violations be corrected? -
ANSWER-Violations can be corrected manually or
automatically using SQL constraints such as RESTRICT,
SET NULL, SET DEFAULT, or CASCADE.
What does the RESTRICT constraint do in SQL? -
ANSWER-The RESTRICT constraint rejects any insert,
update, or delete operation that violates referential
integrity.
What does the SET NULL constraint do in SQL? -
ANSWER-The SET NULL constraint sets invalid foreign
keys to NULL when the referenced primary key is deleted
or updated.
, 4|Page
What does the SET DEFAULT constraint do in SQL? -
ANSWER-The SET DEFAULT constraint sets invalid
foreign keys to their default value when the referenced
primary key is deleted or updated.
What does the CASCADE constraint do in SQL? -
ANSWER-The CASCADE constraint propagates primary
key changes to foreign keys. If a primary key is deleted,
matching foreign keys are also deleted. If a primary key is
updated, matching foreign keys are updated to the new
value.
What do the ON DELETE and ON UPDATE clauses
specify in a FOREIGN KEY constraint? - ANSWER-The
ON DELETE and ON UPDATE clauses specify the actions
