1
WGU D427 Database Management
Applications Exam 2025 – Pre-
Assessment & Objective Assessment
with Verified Answers | Updated for
Guaranteed Pass
Below is a set of 200 realistic multiple-choice questions designed for the WGU D427 Database
Management Applications Exam 2025, divided into two sections: 100 questions for the Pre-
Assessment and 100 questions for the Objective Assessment. Each question aligns with the
course competencies, focusing on SQL, database design, data manipulation, and management
concepts as outlined in the WGU D427 curriculum. The questions incorporate key topics such as
CRUD operations, SQL syntax, joins, data types, normalization, and database administration.
Each question includes four answer options, with the correct answer in blue, followed by an
expert rationale based on database management principles.
Pre-Assessment Questions (1–100)
1. Which SQL command is used to create a new database table?
o A) INSERT
o B) CREATE
o C) UPDATE
o D) DELETE
Rationale: The CREATE command is a Data Definition Language (DDL) statement used
to define the structure of a new table in a database. INSERT, UPDATE, and DELETE are
Data Manipulation Language (DML) commands for managing data, not creating tables.
2. What does the acronym CRUD stand for in database management?
o A) Create, Retrieve, Update, Drop
o B) Create, Read, Update, Delete
o C) Construct, Read, Update, Destroy
o D) Create, Retrieve, Undo, Delete
Rationale: CRUD represents the four basic operations for managing data in a database:
Create (adding new records), Read (retrieving data), Update (modifying data), and Delete
(removing data).
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3. Which data type is most appropriate for storing the date "2025-06-28" without time
information?
o A) DATETIME
o B) DATE
o C) VARCHAR
o D) INTEGER
Rationale: The DATE data type stores dates in the format YYYY-MM-DD without time
information, making it ideal for "2025-06-28". DATETIME includes time, VARCHAR is
for strings, and INTEGER is for numbers.
4. How many attributes are present in the address fragment "Seattle, WA 98111
USA"?
o A) 1
o B) 2
o C) 4
o D) 3
Rationale: The address fragment can be broken into four attributes: city (Seattle), state
(WA), ZIP code (98111), and country (USA). Each represents a distinct component of the
address.
5. Which column should be designated as the primary key for a table with columns:
Weight (decimal), Description (varchar), LastChangedDate (date),
TrackingNumber (integer)?
o A) Weight
o B) Description
o C) LastChangedDate
o D) TrackingNumber
Rationale: The TrackingNumber, as an integer, is unique and suitable for a primary key
to identify each record uniquely. Weight, Description, and LastChangedDate are not
guaranteed to be unique.
6. Which SQL command is an example of Data Definition Language (DDL)?
o A) SELECT
o B) ALTER
o C) UPDATE
o D) DELETE
Rationale: ALTER is a DDL command used to modify table structures. SELECT,
UPDATE, and DELETE are DML commands for data manipulation.
7. What is the correct syntax to add a column named "Producer" with VARCHAR(50)
to the Movie table?
o A) ADD COLUMN Producer VARCHAR(50) TO Movie
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o B) ALTER TABLE Movie ADD Producer VARCHAR(50)
o C) MODIFY TABLE Movie ADD Producer VARCHAR(50)
o D) INSERT INTO Movie Producer VARCHAR(50)
Rationale: The ALTER TABLE statement with ADD is used to add a new column to an
existing table. The correct syntax is ALTER TABLE table_name ADD column_name
data_type.
8. Which SQL statement retrieves all columns from the Employee table where the
salary is greater than 50000?
o A) SELECT * FROM Employee WHERE salary > 50000
o B) SELECT * FROM Employee WHERE salary > 50000;
o C) SELECT ALL FROM Employee WHERE salary > 50000
o D) SELECT FROM Employee WHERE salary > 50000
Rationale: The correct syntax for retrieving all columns is SELECT * FROM
table_name WHERE condition, with a semicolon to terminate the statement.
9. What does the DECIMAL(5,2) data type indicate?
o A) 5 digits total, no decimal places
o B) 5 digits total, 2 after the decimal
o C) 5 digits before the decimal, 2 after
o D) 2 digits total, 5 after the decimal
Rationale: DECIMAL(5,2) means a total of 5 digits, with 2 digits after the decimal point
(e.g., 123.45).
10. Which SQL clause is used to sort query results in ascending order?
o A) GROUP BY
o B) ORDER BY
o C) WHERE
o D) HAVING
Rationale: The ORDER BY clause sorts query results, with ASC (ascending) as the
default order. GROUP BY aggregates data, WHERE filters rows, and HAVING filters
grouped data.
11. Which SQL statement deletes the Genre column from the Movie table?
o A) ALTER TABLE Movie DELETE Genre
o B) ALTER TABLE Movie DROP COLUMN Genre
o C) DROP TABLE Movie Genre
o D) DELETE FROM Movie Genre
Rationale: The ALTER TABLE statement with DROP COLUMN removes a specific
column from a table.
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12. What is the purpose of a primary key in a database table?
o A) To store large text data
o B) To uniquely identify each record
o C) To allow duplicate records
o D) To index all columns
Rationale: A primary key ensures each record in a table is uniquely identifiable and
prevents duplicates.
13. Which SQL statement inserts a new record into the Customer table with
Name='John' and City='Chicago'?
o A) INSERT INTO Customer (Name, City) VALUES ('John', 'Chicago')
o B) INSERT INTO Customer (Name, City) VALUES ('John', 'Chicago');
o C) ADD Customer (Name, City) VALUES ('John', 'Chicago')
o D) INSERT Customer SET Name='John', City='Chicago'
Rationale: The INSERT INTO statement with VALUES adds a new record, and a
semicolon terminates the statement.
14. Which join type includes all rows from the left table and matching rows from the
right table?
o A) INNER JOIN
o B) LEFT JOIN
o C) RIGHT JOIN
o D) FULL JOIN
Rationale: A LEFT JOIN includes all rows from the left table, with NULLs for non-
matching rows from the right table.
15. What is the result of the query: SELECT COUNT(*) FROM Employee WHERE
department='IT'?
o A) The number of employees in the IT department
o B) The total salary of IT employees
o C) All records from the Employee table
o D) The number of departments
Rationale: The COUNT(*) function returns the number of rows meeting the WHERE
condition, in this case, employees in the IT department.
16. Which SQL statement creates a view named MyMusic with Title and Genre from
the Song table?
o A) CREATE VIEW MyMusic AS SELECT Title, Genre FROM Song
o B) CREATE VIEW MyMusic AS SELECT Title, Genre FROM Song;
o C) CREATE TABLE MyMusic AS SELECT Title, Genre FROM Song
o D) SELECT VIEW MyMusic AS Title, Genre FROM Song
WGU D427 Database Management
Applications Exam 2025 – Pre-
Assessment & Objective Assessment
with Verified Answers | Updated for
Guaranteed Pass
Below is a set of 200 realistic multiple-choice questions designed for the WGU D427 Database
Management Applications Exam 2025, divided into two sections: 100 questions for the Pre-
Assessment and 100 questions for the Objective Assessment. Each question aligns with the
course competencies, focusing on SQL, database design, data manipulation, and management
concepts as outlined in the WGU D427 curriculum. The questions incorporate key topics such as
CRUD operations, SQL syntax, joins, data types, normalization, and database administration.
Each question includes four answer options, with the correct answer in blue, followed by an
expert rationale based on database management principles.
Pre-Assessment Questions (1–100)
1. Which SQL command is used to create a new database table?
o A) INSERT
o B) CREATE
o C) UPDATE
o D) DELETE
Rationale: The CREATE command is a Data Definition Language (DDL) statement used
to define the structure of a new table in a database. INSERT, UPDATE, and DELETE are
Data Manipulation Language (DML) commands for managing data, not creating tables.
2. What does the acronym CRUD stand for in database management?
o A) Create, Retrieve, Update, Drop
o B) Create, Read, Update, Delete
o C) Construct, Read, Update, Destroy
o D) Create, Retrieve, Undo, Delete
Rationale: CRUD represents the four basic operations for managing data in a database:
Create (adding new records), Read (retrieving data), Update (modifying data), and Delete
(removing data).
, 2
3. Which data type is most appropriate for storing the date "2025-06-28" without time
information?
o A) DATETIME
o B) DATE
o C) VARCHAR
o D) INTEGER
Rationale: The DATE data type stores dates in the format YYYY-MM-DD without time
information, making it ideal for "2025-06-28". DATETIME includes time, VARCHAR is
for strings, and INTEGER is for numbers.
4. How many attributes are present in the address fragment "Seattle, WA 98111
USA"?
o A) 1
o B) 2
o C) 4
o D) 3
Rationale: The address fragment can be broken into four attributes: city (Seattle), state
(WA), ZIP code (98111), and country (USA). Each represents a distinct component of the
address.
5. Which column should be designated as the primary key for a table with columns:
Weight (decimal), Description (varchar), LastChangedDate (date),
TrackingNumber (integer)?
o A) Weight
o B) Description
o C) LastChangedDate
o D) TrackingNumber
Rationale: The TrackingNumber, as an integer, is unique and suitable for a primary key
to identify each record uniquely. Weight, Description, and LastChangedDate are not
guaranteed to be unique.
6. Which SQL command is an example of Data Definition Language (DDL)?
o A) SELECT
o B) ALTER
o C) UPDATE
o D) DELETE
Rationale: ALTER is a DDL command used to modify table structures. SELECT,
UPDATE, and DELETE are DML commands for data manipulation.
7. What is the correct syntax to add a column named "Producer" with VARCHAR(50)
to the Movie table?
o A) ADD COLUMN Producer VARCHAR(50) TO Movie
, 3
o B) ALTER TABLE Movie ADD Producer VARCHAR(50)
o C) MODIFY TABLE Movie ADD Producer VARCHAR(50)
o D) INSERT INTO Movie Producer VARCHAR(50)
Rationale: The ALTER TABLE statement with ADD is used to add a new column to an
existing table. The correct syntax is ALTER TABLE table_name ADD column_name
data_type.
8. Which SQL statement retrieves all columns from the Employee table where the
salary is greater than 50000?
o A) SELECT * FROM Employee WHERE salary > 50000
o B) SELECT * FROM Employee WHERE salary > 50000;
o C) SELECT ALL FROM Employee WHERE salary > 50000
o D) SELECT FROM Employee WHERE salary > 50000
Rationale: The correct syntax for retrieving all columns is SELECT * FROM
table_name WHERE condition, with a semicolon to terminate the statement.
9. What does the DECIMAL(5,2) data type indicate?
o A) 5 digits total, no decimal places
o B) 5 digits total, 2 after the decimal
o C) 5 digits before the decimal, 2 after
o D) 2 digits total, 5 after the decimal
Rationale: DECIMAL(5,2) means a total of 5 digits, with 2 digits after the decimal point
(e.g., 123.45).
10. Which SQL clause is used to sort query results in ascending order?
o A) GROUP BY
o B) ORDER BY
o C) WHERE
o D) HAVING
Rationale: The ORDER BY clause sorts query results, with ASC (ascending) as the
default order. GROUP BY aggregates data, WHERE filters rows, and HAVING filters
grouped data.
11. Which SQL statement deletes the Genre column from the Movie table?
o A) ALTER TABLE Movie DELETE Genre
o B) ALTER TABLE Movie DROP COLUMN Genre
o C) DROP TABLE Movie Genre
o D) DELETE FROM Movie Genre
Rationale: The ALTER TABLE statement with DROP COLUMN removes a specific
column from a table.
, 4
12. What is the purpose of a primary key in a database table?
o A) To store large text data
o B) To uniquely identify each record
o C) To allow duplicate records
o D) To index all columns
Rationale: A primary key ensures each record in a table is uniquely identifiable and
prevents duplicates.
13. Which SQL statement inserts a new record into the Customer table with
Name='John' and City='Chicago'?
o A) INSERT INTO Customer (Name, City) VALUES ('John', 'Chicago')
o B) INSERT INTO Customer (Name, City) VALUES ('John', 'Chicago');
o C) ADD Customer (Name, City) VALUES ('John', 'Chicago')
o D) INSERT Customer SET Name='John', City='Chicago'
Rationale: The INSERT INTO statement with VALUES adds a new record, and a
semicolon terminates the statement.
14. Which join type includes all rows from the left table and matching rows from the
right table?
o A) INNER JOIN
o B) LEFT JOIN
o C) RIGHT JOIN
o D) FULL JOIN
Rationale: A LEFT JOIN includes all rows from the left table, with NULLs for non-
matching rows from the right table.
15. What is the result of the query: SELECT COUNT(*) FROM Employee WHERE
department='IT'?
o A) The number of employees in the IT department
o B) The total salary of IT employees
o C) All records from the Employee table
o D) The number of departments
Rationale: The COUNT(*) function returns the number of rows meeting the WHERE
condition, in this case, employees in the IT department.
16. Which SQL statement creates a view named MyMusic with Title and Genre from
the Song table?
o A) CREATE VIEW MyMusic AS SELECT Title, Genre FROM Song
o B) CREATE VIEW MyMusic AS SELECT Title, Genre FROM Song;
o C) CREATE TABLE MyMusic AS SELECT Title, Genre FROM Song
o D) SELECT VIEW MyMusic AS Title, Genre FROM Song
