WGU D427 DATABASE MANAGEMENT FULL
SOLUTION PAPER 2026 QUESTIONS WITH
ANSWERS GRADED A+
◉What is the EXISTS clause purpose? Answer: Returns True if the
subquery returns at least one row.
Example:
SELECT CourseId
FROM Course C
WHERE EXISTS
(SELECT *
FROM Instructor
WHERE InstructorId = C.InstructorId);
◉What is a Correlated Subquery? Answer: A subquery that
references the outer query.
Example:
SELECT *
FROM Instructor I
, WHERE 2 <=
(SELECT COUNT(*)
FROM Course
WHERE InstructorId = I.InstructorId);
◉How do you rename a column in a query result? Answer: Use the
AS (alias)
Example:
SELECT CourseName AS Name
FROM Course;
◉What is a Column alias? Answer: A temporary name for a column
in the query result.
◉Can SQL aliases contain spaces? Answer: Yes, if placed in
quotations.
Example:
SELECT CourseName AS "Course Title"
FROM Course;
SOLUTION PAPER 2026 QUESTIONS WITH
ANSWERS GRADED A+
◉What is the EXISTS clause purpose? Answer: Returns True if the
subquery returns at least one row.
Example:
SELECT CourseId
FROM Course C
WHERE EXISTS
(SELECT *
FROM Instructor
WHERE InstructorId = C.InstructorId);
◉What is a Correlated Subquery? Answer: A subquery that
references the outer query.
Example:
SELECT *
FROM Instructor I
, WHERE 2 <=
(SELECT COUNT(*)
FROM Course
WHERE InstructorId = I.InstructorId);
◉How do you rename a column in a query result? Answer: Use the
AS (alias)
Example:
SELECT CourseName AS Name
FROM Course;
◉What is a Column alias? Answer: A temporary name for a column
in the query result.
◉Can SQL aliases contain spaces? Answer: Yes, if placed in
quotations.
Example:
SELECT CourseName AS "Course Title"
FROM Course;
