WGU D427 Core Complete Modules & Topics Verified Multiple Choice and Conceptual Actual Emended Exam Questions With Reviewed 100% Correct Detailed Answers Guaranteed Pass!!Current Update!!

WGU D427 Core Complete Modules & Topics
Verified Multiple Choice and Conceptual Actual
Emended Exam Questions With Reviewed
100% Correct Detailed Answers

Guaranteed Pass!!Current Update!!


1. SQL Command Types & DDL Operations

• Writing and executing Data Definition Language (DDL) queries:

o CREATE TABLE, ALTER TABLE, and DROP TABLE statements

• Working with column operations, including:

o Adding (ADD COLUMN), modifying (CHANGE), or removing (DROP COLUMN) columns

2. CRUD & Data Manipulation (DML)

• Creating, reading, updating, and deleting data:

o INSERT, UPDATE, DELETE

• Using DESCRIBE table_name; to verify structure post-change



3. Aggregate Functions & Deletion Constructs

• Writing SQL with:

o Aggregate functions like MIN(), MAX(), SUM(), etc.

o DELETE operations based on conditions (e.g., deleting rows meeting criteria)



4. Subqueries & Query Self-Checking

• Mastering nested queries and subquery logic

• Use of safety checks:

o Running SELECT * FROM table_name; before and after modifying statements for result
validation

,5. Joins & Data Retrieval

• Understanding and implementing:

o INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL OUTER JOIN, CROSS JOIN

• Writing multi-table joins to retrieve combined data

6. Views & Referential Integrity

• Creating and managing views (including materialized views)

• DDL-level understanding of referential behaviors:

o ON DELETE CASCADE vs. ON DELETE RESTRICT

7. Primary Key & Data Modeling

• Defining Primary Keys, Foreign Keys, and Auto-Increment behavior

• Ensuring data model integrity and proper relational constraints

8. Query Filtering, Sorting & Grouping

• Utilizing:

o BETWEEN, LIKE, GROUP BY, HAVING, and ORDER BY

• Filtering query results effectively

9. Lab-Based Practice & Assessment Preparation

• Heavy reliance on Zybooks Lab Exercises (Chapters 7 & 8) as practical stepping stones for
learning and preparing for the objective assessment

• Writing and testing SQL commands in real scenarios, often experiencing near-identical tasks
on the OA

10. Objective Assessment (OA) Strategy

• Expect ~25-question exam with:

o ~60–70% SQL coding tasks (DDL, DML, joins, functions)

o ~30–40% multiple-choice questions (conceptual understanding)

• Key tactics:

o Double-check code via DESCRIBE or SELECT *

o Be precise with syntax—punctuation matters

,Q1. Which SQL command type is used to define and manage database structures
such as tables and schemas?
A. DML
B. DQL
C. DDL
D. TCL
Answer: C

Q2. Which SQL command type modifies data stored in tables (INSERT, UPDATE,
DELETE)?
A. DCL
B. DDL
C. DML
D. DQL
Answer: C
Q3. Which SQL sublanguage includes SELECT statements used to query data?
A. DML
B. DQL
C. DDL
D. TCL
Answer: B
Q4. Which SQL command type is used for granting and revoking user privileges?
A. DCL
B. DML
C. DQL
D. DDL
Answer: A
Q5. Which SQL command type includes COMMIT, ROLLBACK, and SAVEPOINT?
A. TCL
B. DML

, C. DDL
D. DCL
Answer: A


CREATE TABLE
Q6. What does the CREATE TABLE statement do?
A. Inserts new rows into a table
B. Defines a new table with specified columns and data types
C. Modifies data in an existing table
D. Deletes all rows from a table
Answer: B
Q7. Which SQL command creates a table named Students with columns id (INT)
and name (VARCHAR)?
A. CREATE TABLE Students (id INT, name VARCHAR(50));
B. INSERT INTO Students (id, name);
C. ADD TABLE Students (id INT, name VARCHAR(50));
D. ALTER TABLE Students (id INT, name VARCHAR(50));
Answer: A
Q8. What happens if you try to create a table that already exists without using IF
NOT EXISTS?
A. SQL automatically overwrites the old table
B. An error is thrown
C. The command is ignored
D. The old table is truncated
Answer: B
Q9. Which constraint ensures that a column cannot contain NULL values?
A. UNIQUE
B. NOT NULL
C. PRIMARY KEY