WGU D426 DATA MANAGEMENT
FOUNDATIONS ADVANCED PRACTICE
EXAM QUESTIONS AND ANSWERS
1. In the context of the relational model, what specific property ensures that every row in a
table is unique?
A. Primary Key
B. Foreign Key
C. Index
D. Domain Constraint
Answer: A
Conceptual Explanation: A Primary Key is a unique identifier for each record in a
database table. It must contain unique values and cannot contain NULL values, ensuring
entity integrity.
2. Which normal form is specifically concerned with removing partial functional
dependencies?
A. Second Normal Form (2NF)
,B. First Normal Form (1NF)
C. Third Normal Form (3NF)
D. Boyce-Codd Normal Form (BCNF)
Answer: A
Conceptual Explanation: Second Normal Form (2NF) requires that the table is in 1NF and
all non-key attributes are fully functional dependent on the primary key, thereby removing
partial dependencies.
3. Which SQL statement is used to remove all records from a table without deleting the table
structure itself?
A. DROP
B. TRUNCATE
C. DELETE
D. REMOVE
Answer: B
Conceptual Explanation: TRUNCATE is a DDL command that deletes all rows from a table,
but the table structure and its columns, constraints, and indexes remain intact.
4. What is the result of a Cartesian Product (Cross Join) between two tables with 5 rows and
10 rows respectively?
A. 15 rows
, B. 5 rows
C. 50 rows
D. 10 rows
Answer: C
Conceptual Explanation: A Cartesian Product returns every possible combination of rows
from the tables. 5 multiplied by 10 equals 50 rows.
5. In an Entity-Relationship Diagram (ERD), a ‘weak entity’ is characterized by what?
A. It cannot contain a foreign key.
B. It contains only one attribute.
C. It is used to link two many-to-many tables.
D. It has no primary key and depends on a strong entity for identification.
Answer: D
Conceptual Explanation: A weak entity is an entity that cannot be uniquely identified by
its attributes alone and relies on a relationship with another entity (the owner) to form a
primary key.
6. Which SQL command would you use to change the data type of an existing column in a
table?
A. UPDATE TABLE
B. MODIFY COLUMN
FOUNDATIONS ADVANCED PRACTICE
EXAM QUESTIONS AND ANSWERS
1. In the context of the relational model, what specific property ensures that every row in a
table is unique?
A. Primary Key
B. Foreign Key
C. Index
D. Domain Constraint
Answer: A
Conceptual Explanation: A Primary Key is a unique identifier for each record in a
database table. It must contain unique values and cannot contain NULL values, ensuring
entity integrity.
2. Which normal form is specifically concerned with removing partial functional
dependencies?
A. Second Normal Form (2NF)
,B. First Normal Form (1NF)
C. Third Normal Form (3NF)
D. Boyce-Codd Normal Form (BCNF)
Answer: A
Conceptual Explanation: Second Normal Form (2NF) requires that the table is in 1NF and
all non-key attributes are fully functional dependent on the primary key, thereby removing
partial dependencies.
3. Which SQL statement is used to remove all records from a table without deleting the table
structure itself?
A. DROP
B. TRUNCATE
C. DELETE
D. REMOVE
Answer: B
Conceptual Explanation: TRUNCATE is a DDL command that deletes all rows from a table,
but the table structure and its columns, constraints, and indexes remain intact.
4. What is the result of a Cartesian Product (Cross Join) between two tables with 5 rows and
10 rows respectively?
A. 15 rows
, B. 5 rows
C. 50 rows
D. 10 rows
Answer: C
Conceptual Explanation: A Cartesian Product returns every possible combination of rows
from the tables. 5 multiplied by 10 equals 50 rows.
5. In an Entity-Relationship Diagram (ERD), a ‘weak entity’ is characterized by what?
A. It cannot contain a foreign key.
B. It contains only one attribute.
C. It is used to link two many-to-many tables.
D. It has no primary key and depends on a strong entity for identification.
Answer: D
Conceptual Explanation: A weak entity is an entity that cannot be uniquely identified by
its attributes alone and relies on a relationship with another entity (the owner) to form a
primary key.
6. Which SQL command would you use to change the data type of an existing column in a
table?
A. UPDATE TABLE
B. MODIFY COLUMN
