WGU D427 ZLO1 A.
Objective Assessment
(ACTUAL Exam
1. Which SQL statement retrieves all columns from the Employee table where the
department is “Sales”?
A. SELECT * FROM Employee WHERE department = 'Sales';
B. SELECT department FROM Employee WHERE department = Sales;
C. SELECT * Employee department='Sales';
D. SELECT ALL Employee WHERE department = 'Sales';
Answer: A
Explanation: Correct SQL syntax uses SELECT * FROM table WHERE condition;.
2. What type of relationship exists between Customer and Order in a sales database?
A. One-to-One
B. One-to-Many
C. Many-to-Many
D. Recursive
Answer: B
Explanation: One customer can have many orders, but each order belongs to one
customer.
3. Which of the following best describes a foreign key?
,A. A field that uniquely identifies each record
B. A field that links to a primary key in another table
C. A key used to encrypt data
D. A key automatically incremented by the system
Answer: B
Explanation: Foreign keys establish referential integrity between related tables.
4. Which SQL command is used to add a new record into a table?
A. INSERT INTO
B. ADD RECORD
C. CREATE ROW
D. UPDATE
Answer: A
Explanation: INSERT INTO table (columns) VALUES (values); adds new rows to a
table.
5. In an ERD, a diamond shape represents:
A. Attribute
B. Entity
C. Relationship
D. Primary key
Answer: C
Explanation: Diamonds in ERDs represent relationships between entities.
6. Which normalization form removes partial dependency on part of a composite
key?
A. 1NF
B. 2NF
C. 3NF
, D. BCNF
Answer: B
Explanation: Second Normal Form eliminates partial dependency on a composite
primary key.
7. A composite key is:
A. A key made of multiple columns
B. A foreign key from another table
C. A unique constraint on a single column
D. A surrogate key
Answer: A
Explanation: Composite keys combine two or more attributes to uniquely identify
records.
8. What does ETL stand for in data warehousing?
A. Extract, Transform, Load
B. Export, Transfer, Link
C. Extract, Translate, Load
D. Encode, Transfer, Locate
Answer: A
Explanation: ETL is the standard process of moving data into a data warehouse.
9. Which SQL function returns the total number of rows in a table?
A. COUNT()
B. SUM()
C. TOTAL()
D. ROWCOUNT()
Answer: A
Explanation: COUNT(*) counts all rows; COUNT(column) counts non-null values.
Objective Assessment
(ACTUAL Exam
1. Which SQL statement retrieves all columns from the Employee table where the
department is “Sales”?
A. SELECT * FROM Employee WHERE department = 'Sales';
B. SELECT department FROM Employee WHERE department = Sales;
C. SELECT * Employee department='Sales';
D. SELECT ALL Employee WHERE department = 'Sales';
Answer: A
Explanation: Correct SQL syntax uses SELECT * FROM table WHERE condition;.
2. What type of relationship exists between Customer and Order in a sales database?
A. One-to-One
B. One-to-Many
C. Many-to-Many
D. Recursive
Answer: B
Explanation: One customer can have many orders, but each order belongs to one
customer.
3. Which of the following best describes a foreign key?
,A. A field that uniquely identifies each record
B. A field that links to a primary key in another table
C. A key used to encrypt data
D. A key automatically incremented by the system
Answer: B
Explanation: Foreign keys establish referential integrity between related tables.
4. Which SQL command is used to add a new record into a table?
A. INSERT INTO
B. ADD RECORD
C. CREATE ROW
D. UPDATE
Answer: A
Explanation: INSERT INTO table (columns) VALUES (values); adds new rows to a
table.
5. In an ERD, a diamond shape represents:
A. Attribute
B. Entity
C. Relationship
D. Primary key
Answer: C
Explanation: Diamonds in ERDs represent relationships between entities.
6. Which normalization form removes partial dependency on part of a composite
key?
A. 1NF
B. 2NF
C. 3NF
, D. BCNF
Answer: B
Explanation: Second Normal Form eliminates partial dependency on a composite
primary key.
7. A composite key is:
A. A key made of multiple columns
B. A foreign key from another table
C. A unique constraint on a single column
D. A surrogate key
Answer: A
Explanation: Composite keys combine two or more attributes to uniquely identify
records.
8. What does ETL stand for in data warehousing?
A. Extract, Transform, Load
B. Export, Transfer, Link
C. Extract, Translate, Load
D. Encode, Transfer, Locate
Answer: A
Explanation: ETL is the standard process of moving data into a data warehouse.
9. Which SQL function returns the total number of rows in a table?
A. COUNT()
B. SUM()
C. TOTAL()
D. ROWCOUNT()
Answer: A
Explanation: COUNT(*) counts all rows; COUNT(column) counts non-null values.
