WGU C175/D426 DATA
MANAGEMENT FOUNDATIONS
PRACTICE EXAM
Topics Covered: Database Fundamentals, Relational Model, SQL
(DDL, DML, DQL), Normalization (1NF, 2NF, 3NF), Entity-
Relationship (ER) Modeling, Data Integrity, Indexing, Data
Warehousing, and ETL.
1. A company wants to track customer orders. Each order can contain multiple products, and each
product can appear on multiple orders. In an Entity-Relationship (ER) diagram, what type of
relationship is described between "Order" and "Product"?
a) One-to-One
b) One-to-Many
c) Many-to-One
d) Many-to-Many
Answer: d) Many-to-Many
Rationale: The description states that one order can have many products and one product can be on
many orders. This bidirectional many-to-one definition is the definition of a many-to-many relationship.
In a physical database, this is typically resolved using a junction (or associative) table.
2. Which of the following SQL commands is used to remove an entire table from the database,
including its structure and data?
a) DELETE FROM Customers;
b) TRUNCATE TABLE Customers;
c) DROP TABLE Customers;
d) ALTER TABLE Customers;
,Answer: c) DROP TABLE Customers;
Rationale: DROP is a Data Definition Language (DDL) command used to remove database objects like
tables, views, or indexes. DELETE removes rows but keeps the structure, and TRUNCATE removes all
rows but also keeps the structure for future use. ALTER is used to modify the structure of an existing
table.
3. A table is in Second Normal Form (2NF). Which of the following conditions must be TRUE?
a) It contains no repeating groups.
b) It has no partial dependencies.
c) It has no transitive dependencies.
d) It contains only atomic values.
Answer: b) It has no partial dependencies.
Rationale: For a table to be in 2NF, it must first be in 1NF (which addresses repeating groups and atomic
values). Then, 2NF requires that every non-key attribute is fully functionally dependent on
the entire primary key. This means there are no partial dependencies, where an attribute depends on
only part of a composite primary key.
4. In an ER diagram, what does the symbol (0, M) next to an entity represent?
a) The entity has a maximum cardinality of M and a minimum cardinality of 0.
b) The entity has a maximum modality of M and a minimum modality of 0.
c) The entity is mandatory and has many instances.
d) The entity is optional and can be related to many instances of the other entity.
Answer: d) The entity is optional and can be related to many instances of the other entity.
Rationale: In ER diagram notation, (min, max) is used to represent the cardinality and modality. The first
number is the minimum number of times an instance can be associated (modality, 0=optional,
1=mandatory). The second number is the maximum number of times it can be associated (cardinality,
1=one, M=many). So (0, M) means the relationship is optional and can involve many instances.
5. Which of the following is an example of unstructured data?
a) A table of customer names and addresses.
b) A video file of a product demonstration.
c) A spreadsheet of quarterly sales figures.
d) A row in a database containing an order ID and product ID.
Answer: b) A video file of a product demonstration.
Rationale: Unstructured data is information that does not have a predefined data model or is not
organized in a pre-defined manner. Video files, images, audio files, and text documents are classic
examples. The other options are highly structured, fitting neatly into rows and columns.
, 6. The DBMS function that translates logical user requests into physical commands that read and write
data to storage is known as:
a) Security Management
b) Data Integrity Management
c) Data Storage Management
d) Data Dictionary Management
Answer: c) Data Storage Management
Rationale: Data storage management is a core DBMS function that handles how data is physically stored
on storage devices. It manages the complexities of the file system, providing a logical view to users and
applications while managing the physical input/output operations.
7. What is the primary purpose of the GROUP BY clause in SQL?
a) To filter rows before they are grouped.
b) To sort the result set in a specific order.
c) To combine rows into groups based on common column values, often for use with aggregate
functions.
d) To eliminate duplicate rows from the result set.
Answer: c) To combine rows into groups based on common column values, often for use with
aggregate functions.
Rationale: GROUP BY is used with aggregate functions like COUNT, AVG, SUM, etc., to group the result
set by one or more columns. For example, SELECT COUNT(*), City FROM Customers GROUP BY
City; would give you the number of customers in each city.
8. Which of the following violates the rules of Referential Integrity?
a) Inserting a new row into the "Orders" table with a CustomerID that exists in the "Customers" table.
b) Deleting a row from the "Customers" table that has related rows in the "Orders" table without using
a CASCADE or SET NULL rule.
c) Updating a CustomerID in the "Customers" table and having the change automatically reflected in the
"Orders" table.
d) Inserting a new row into the "Customers" table with a CustomerID that doesn't match any existing
foreign key.
Answer: b) Deleting a row from the "Customers" table that has related rows in the "Orders" table
without using a CASCADE or SET NULL rule.
Rationale: Referential integrity ensures that relationships between tables remain consistent. Deleting a
parent record (Customers) that has child records (Orders) creates "orphaned" records, violating the rule
that a foreign key must have a valid primary key reference.
9. Which join type would return all rows from the left table, and the matched rows from the right
table, filling with NULL for non-matching rows on the right?
MANAGEMENT FOUNDATIONS
PRACTICE EXAM
Topics Covered: Database Fundamentals, Relational Model, SQL
(DDL, DML, DQL), Normalization (1NF, 2NF, 3NF), Entity-
Relationship (ER) Modeling, Data Integrity, Indexing, Data
Warehousing, and ETL.
1. A company wants to track customer orders. Each order can contain multiple products, and each
product can appear on multiple orders. In an Entity-Relationship (ER) diagram, what type of
relationship is described between "Order" and "Product"?
a) One-to-One
b) One-to-Many
c) Many-to-One
d) Many-to-Many
Answer: d) Many-to-Many
Rationale: The description states that one order can have many products and one product can be on
many orders. This bidirectional many-to-one definition is the definition of a many-to-many relationship.
In a physical database, this is typically resolved using a junction (or associative) table.
2. Which of the following SQL commands is used to remove an entire table from the database,
including its structure and data?
a) DELETE FROM Customers;
b) TRUNCATE TABLE Customers;
c) DROP TABLE Customers;
d) ALTER TABLE Customers;
,Answer: c) DROP TABLE Customers;
Rationale: DROP is a Data Definition Language (DDL) command used to remove database objects like
tables, views, or indexes. DELETE removes rows but keeps the structure, and TRUNCATE removes all
rows but also keeps the structure for future use. ALTER is used to modify the structure of an existing
table.
3. A table is in Second Normal Form (2NF). Which of the following conditions must be TRUE?
a) It contains no repeating groups.
b) It has no partial dependencies.
c) It has no transitive dependencies.
d) It contains only atomic values.
Answer: b) It has no partial dependencies.
Rationale: For a table to be in 2NF, it must first be in 1NF (which addresses repeating groups and atomic
values). Then, 2NF requires that every non-key attribute is fully functionally dependent on
the entire primary key. This means there are no partial dependencies, where an attribute depends on
only part of a composite primary key.
4. In an ER diagram, what does the symbol (0, M) next to an entity represent?
a) The entity has a maximum cardinality of M and a minimum cardinality of 0.
b) The entity has a maximum modality of M and a minimum modality of 0.
c) The entity is mandatory and has many instances.
d) The entity is optional and can be related to many instances of the other entity.
Answer: d) The entity is optional and can be related to many instances of the other entity.
Rationale: In ER diagram notation, (min, max) is used to represent the cardinality and modality. The first
number is the minimum number of times an instance can be associated (modality, 0=optional,
1=mandatory). The second number is the maximum number of times it can be associated (cardinality,
1=one, M=many). So (0, M) means the relationship is optional and can involve many instances.
5. Which of the following is an example of unstructured data?
a) A table of customer names and addresses.
b) A video file of a product demonstration.
c) A spreadsheet of quarterly sales figures.
d) A row in a database containing an order ID and product ID.
Answer: b) A video file of a product demonstration.
Rationale: Unstructured data is information that does not have a predefined data model or is not
organized in a pre-defined manner. Video files, images, audio files, and text documents are classic
examples. The other options are highly structured, fitting neatly into rows and columns.
, 6. The DBMS function that translates logical user requests into physical commands that read and write
data to storage is known as:
a) Security Management
b) Data Integrity Management
c) Data Storage Management
d) Data Dictionary Management
Answer: c) Data Storage Management
Rationale: Data storage management is a core DBMS function that handles how data is physically stored
on storage devices. It manages the complexities of the file system, providing a logical view to users and
applications while managing the physical input/output operations.
7. What is the primary purpose of the GROUP BY clause in SQL?
a) To filter rows before they are grouped.
b) To sort the result set in a specific order.
c) To combine rows into groups based on common column values, often for use with aggregate
functions.
d) To eliminate duplicate rows from the result set.
Answer: c) To combine rows into groups based on common column values, often for use with
aggregate functions.
Rationale: GROUP BY is used with aggregate functions like COUNT, AVG, SUM, etc., to group the result
set by one or more columns. For example, SELECT COUNT(*), City FROM Customers GROUP BY
City; would give you the number of customers in each city.
8. Which of the following violates the rules of Referential Integrity?
a) Inserting a new row into the "Orders" table with a CustomerID that exists in the "Customers" table.
b) Deleting a row from the "Customers" table that has related rows in the "Orders" table without using
a CASCADE or SET NULL rule.
c) Updating a CustomerID in the "Customers" table and having the change automatically reflected in the
"Orders" table.
d) Inserting a new row into the "Customers" table with a CustomerID that doesn't match any existing
foreign key.
Answer: b) Deleting a row from the "Customers" table that has related rows in the "Orders" table
without using a CASCADE or SET NULL rule.
Rationale: Referential integrity ensures that relationships between tables remain consistent. Deleting a
parent record (Customers) that has child records (Orders) creates "orphaned" records, violating the rule
that a foreign key must have a valid primary key reference.
9. Which join type would return all rows from the left table, and the matched rows from the right
table, filling with NULL for non-matching rows on the right?
