WGU D427 — FULL Objective Assessment (Mock OA) | Questions and Answers | 2026 Update | 100% Correct.

WGU D427 — FULL Objective Assessment (Mock OA) |
Questions and Answers | 2026 Update | 100% Correct.

Western Governors University

WGU D427 — FULL Objective Assessment (Mock OA)

Time Limit: ⏱️ 120 minutes
Questions: 55
Format: Multiple Choice & Multiple Select
Passing Style: Competency-based (≈70%)



📌 INSTRUCTIONS (REAL OA STYLE)

 Choose the best answer.

 Some questions are Multiple Select (clearly marked).

 No partial credit on multiple-select questions.

 SQL syntax is standard ANSI SQL.



📝 QUESTIONS



🔹 SQL BASICS & DML (Q1–Q20)

1. Which keyword returns only unique rows?
A. UNIQUE
B. DISTINCT
C. ONLY
D. FILTER

2. Which clause filters rows before aggregation?
A. WHERE
B. HAVING
C. GROUP BY
D. ORDER BY

3. What does this query return?

SELECT COUNT(salary) FROM employees;

, A. Number of rows including NULLs
B. Number of rows excluding NULLs
C. Average salary
D. Maximum salary

4. Which command adds new rows to a table?
A. ADD
B. UPDATE
C. INSERT
D. APPEND

5. Which SQL command removes rows conditionally?
A. DROP
B. DELETE
C. TRUNCATE
D. REMOVE

6. Which statement updates existing data?
A. ALTER
B. MODIFY
C. UPDATE
D. SET

7. Which clause sorts query results?
A. GROUP BY
B. SORT
C. ORDER BY
D. HAVING

8. Which function returns the largest value?
A. MAX()
B. TOP()
C. HIGH()
D. UPPER()

9. Which operator tests for missing values?
A. = NULL
B. IS NULL
C. NULL()
D. EMPTY

10. What does SELECT * do?
A. Selects only primary keys
B. Selects all rows
C. Selects all columns
D. Selects all tables