WGU D427 – Data Management
Applications OA Exam Questions and
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
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Question 1
What is the primary purpose of a database?
A. To create web pages
B. To organize and store data efficiently
C. To compile computer programs
D. To manage network connections
Correct Answer: B. To organize and store data efficiently
Rationale: A database provides a structured way to store, retrieve, update, and
manage data efficiently.
Question 2
Which SQL statement is used to retrieve data from a table?
A. INSERT
B. UPDATE
C. SELECT
D. DELETE
Correct Answer: C. SELECT
,Rationale: The SELECT statement retrieves one or more rows from a database
table.
Question 3
Which SQL statement is used to add a new row to a table?
A. INSERT
B. CREATE
C. UPDATE
D. SELECT
Correct Answer: A. INSERT
Rationale: INSERT adds new records to an existing table.
Question 4
Which SQL statement modifies existing data?
A. DELETE
B. UPDATE
C. INSERT
D. ALTER
Correct Answer: B. UPDATE
Rationale: UPDATE changes values in existing rows.
Question 5
Which SQL statement removes rows from a table?
A. DROP
B. REMOVE
C. DELETE
D. CLEAR
,Correct Answer: C. DELETE
Rationale: DELETE removes one or more rows while leaving the table structure
intact.
Question 6
Which SQL command creates a new table?
A. CREATE TABLE
B. NEW TABLE
C. MAKE TABLE
D. BUILD TABLE
Correct Answer: A. CREATE TABLE
Rationale: CREATE TABLE defines a new table and its columns.
Question 7
What is a primary key?
A. A duplicate value
B. A column that uniquely identifies each row
C. A foreign table
D. A temporary value
Correct Answer: B. A column that uniquely identifies each row
Rationale: A primary key uniquely identifies every record and cannot contain
duplicate or NULL values.
Question 8
Which characteristic is required for a primary key?
A. Duplicate values
B. NULL values
, C. Unique values
D. Text only
Correct Answer: C. Unique values
Rationale: Every primary key value must be unique to distinguish each row.
Question 9
What is the purpose of a foreign key?
A. Store passwords
B. Link one table to another
C. Sort records
D. Encrypt data
Correct Answer: B. Link one table to another
Rationale: A foreign key establishes a relationship between two tables.
Question 10
Which SQL keyword returns only unique values?
A. UNIQUE
B. DISTINCT
C. ONLY
D. SINGLE
Correct Answer: B. DISTINCT
Rationale: DISTINCT removes duplicate values from query results.
Question 11
Which clause filters rows returned by a query?
A. ORDER BY
B. WHERE
Applications OA Exam Questions and
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
Question 1
What is the primary purpose of a database?
A. To create web pages
B. To organize and store data efficiently
C. To compile computer programs
D. To manage network connections
Correct Answer: B. To organize and store data efficiently
Rationale: A database provides a structured way to store, retrieve, update, and
manage data efficiently.
Question 2
Which SQL statement is used to retrieve data from a table?
A. INSERT
B. UPDATE
C. SELECT
D. DELETE
Correct Answer: C. SELECT
,Rationale: The SELECT statement retrieves one or more rows from a database
table.
Question 3
Which SQL statement is used to add a new row to a table?
A. INSERT
B. CREATE
C. UPDATE
D. SELECT
Correct Answer: A. INSERT
Rationale: INSERT adds new records to an existing table.
Question 4
Which SQL statement modifies existing data?
A. DELETE
B. UPDATE
C. INSERT
D. ALTER
Correct Answer: B. UPDATE
Rationale: UPDATE changes values in existing rows.
Question 5
Which SQL statement removes rows from a table?
A. DROP
B. REMOVE
C. DELETE
D. CLEAR
,Correct Answer: C. DELETE
Rationale: DELETE removes one or more rows while leaving the table structure
intact.
Question 6
Which SQL command creates a new table?
A. CREATE TABLE
B. NEW TABLE
C. MAKE TABLE
D. BUILD TABLE
Correct Answer: A. CREATE TABLE
Rationale: CREATE TABLE defines a new table and its columns.
Question 7
What is a primary key?
A. A duplicate value
B. A column that uniquely identifies each row
C. A foreign table
D. A temporary value
Correct Answer: B. A column that uniquely identifies each row
Rationale: A primary key uniquely identifies every record and cannot contain
duplicate or NULL values.
Question 8
Which characteristic is required for a primary key?
A. Duplicate values
B. NULL values
, C. Unique values
D. Text only
Correct Answer: C. Unique values
Rationale: Every primary key value must be unique to distinguish each row.
Question 9
What is the purpose of a foreign key?
A. Store passwords
B. Link one table to another
C. Sort records
D. Encrypt data
Correct Answer: B. Link one table to another
Rationale: A foreign key establishes a relationship between two tables.
Question 10
Which SQL keyword returns only unique values?
A. UNIQUE
B. DISTINCT
C. ONLY
D. SINGLE
Correct Answer: B. DISTINCT
Rationale: DISTINCT removes duplicate values from query results.
Question 11
Which clause filters rows returned by a query?
A. ORDER BY
B. WHERE
