WGU D427 Data Management Applications OA and
Pre Assessment Actual Exam | Complete Questions
Correct Detailed Answers Verified – Pass
Guaranteed - A+ Graded
Database Fundamentals & Relational Design
Q1: Which of the following best describes the primary function of a Primary Key in a
relational database table?
A. To speed up data retrieval by indexing non-unique values
B. To uniquely identify each record in a table and ensure no two rows are identical
C. To establish a connection to a lookup table containing valid values
D. To allow duplicate values in a column to support data redundancy
Correct Answer: B
Rationale: The best answer is B because the primary purpose of a Primary Key is to
provide a unique identifier for every row in a table, ensuring entity integrity.
Q2: You are reviewing a database schema where a column in the "Orders" table
contains values that must match values in the "Customers" table. What type of
constraint is being applied here?
A. Unique Constraint
B. Check Constraint
C. Foreign Key Constraint
D. Not Null Constraint
Correct Answer: C
Rationale: This choice is correct because a Foreign Key Constraint is specifically used
to enforce referential integrity between two tables by ensuring that values in one column
match valid primary keys in another table.
Q3: In the context of database normalization, what is the main goal of converting a
database to the First Normal Form (1NF)?
A. To ensure that every non-key attribute is dependent on the primary key
B. To eliminate repeating groups and ensure that every column holds atomic (indivisible)
values
C. To remove transitive dependencies between non-key attributes
D. To combine tables with similar data into larger views
Correct Answer: B
,Rationale: The best answer is B because 1NF primarily deals with eliminating repeating
groups of data and ensuring that each field contains only a single, atomic value.
Q4: Which of the following scenarios describes a table that violates Second Normal
Form (2NF)?
A. A table contains a column that is calculated from other columns in the same row
B. A table has a composite primary key, and a non-key attribute depends only on part of
that composite key
C. A table contains a foreign key that references a non-existent primary key in another
table
D. A table allows null values in a column that is designated as a primary key
Correct Answer: B
Rationale: This matches the rule that 2NF requires removing partial dependencies,
meaning all non-key attributes must rely on the entire primary key, not just a portion of it.
Q5: When moving from 2NF to 3NF (Third Normal Form), what specific type of
dependency must be removed?
A. Partial dependency
B. Functional dependency
C. Transitive dependency
D. Multivalued dependency
Correct Answer: C
Rationale: The best answer is C because 3NF is achieved by eliminating transitive
dependencies, where non-key attributes depend on other non-key attributes rather than
directly on the primary key.
Q6: A Student table contains columns: StudentID, Name, Major, and AdvisorName. If
AdvisorName is functionally dependent on Major (i.e., every Major has the same Advisor),
which Normal Form rule is being violated?
A. 1NF
B. 2NF
C. 3NF
D. BCNF
Correct Answer: C
Rationale: This choice is correct because AdvisorName depends on Major (a non-key
attribute) rather than directly on StudentID, which creates a transitive dependency
violating 3NF.
Q7: Which of the following statements accurately describes a Composite Key?
A. It is a single column that uniquely identifies a row due to a unique constraint
, B. It is a primary key consisting of two or more columns used together to uniquely
identify a record
C. It is a surrogate key generated automatically by the database system
D. It is a foreign key that links to multiple different parent tables
Correct Answer: B
Rationale: This query works because a Composite Key is defined as a key that utilizes
two or more columns to create a unique identifier for a row when a single column is
insufficient.
Q8: In an Entity-Relationship (ER) Diagram, what does the "Crow's Foot" notation at the
end of a relationship line typically signify?
A. A "one" side of the relationship
B. A "many" side of the relationship
C. An optional relationship
D. A mandatory relationship
Correct Answer: B
Rationale: The best answer is B because the crow's foot symbol is the standard notation
used to represent the "many" cardinality in data modeling diagrams.
Q9: You need to store data that describes a product with variable attributes like color,
size, and weight, where different products have different attributes. Which design issue
is most likely to arise if you put all these into a single wide table with many nullable
columns?
A. Data redundancy
B. Sparse data and excessive NULLs
C. Circular reference
D. Loss of primary key integrity
Correct Answer: B
Rationale: This choice is correct because using a single table for varying attributes
leads to many empty columns (NULLs) for rows that don't require those specific
attributes, creating a sparse and inefficient table structure.
Q10: Scenario: A vendor provides a raw spreadsheet of sales data that looks like this:
InvoiceID | Date | CustomerName | Item1 | Item2 | Item3 | TotalPrice. The data
for items is repeated across columns. You need to normalize this to 3NF. Which step is
correct?
A. Move CustomerName to a new table and link it using InvoiceID
B. Separate the items into a new LineItems table linked by InvoiceID, and separate
CustomerName into a Customers table linked by CustomerID
C. Simply delete the Item2 and Item3 columns to make the table flatter
D. Add a new primary key to the existing table without changing the column structure
Pre Assessment Actual Exam | Complete Questions
Correct Detailed Answers Verified – Pass
Guaranteed - A+ Graded
Database Fundamentals & Relational Design
Q1: Which of the following best describes the primary function of a Primary Key in a
relational database table?
A. To speed up data retrieval by indexing non-unique values
B. To uniquely identify each record in a table and ensure no two rows are identical
C. To establish a connection to a lookup table containing valid values
D. To allow duplicate values in a column to support data redundancy
Correct Answer: B
Rationale: The best answer is B because the primary purpose of a Primary Key is to
provide a unique identifier for every row in a table, ensuring entity integrity.
Q2: You are reviewing a database schema where a column in the "Orders" table
contains values that must match values in the "Customers" table. What type of
constraint is being applied here?
A. Unique Constraint
B. Check Constraint
C. Foreign Key Constraint
D. Not Null Constraint
Correct Answer: C
Rationale: This choice is correct because a Foreign Key Constraint is specifically used
to enforce referential integrity between two tables by ensuring that values in one column
match valid primary keys in another table.
Q3: In the context of database normalization, what is the main goal of converting a
database to the First Normal Form (1NF)?
A. To ensure that every non-key attribute is dependent on the primary key
B. To eliminate repeating groups and ensure that every column holds atomic (indivisible)
values
C. To remove transitive dependencies between non-key attributes
D. To combine tables with similar data into larger views
Correct Answer: B
,Rationale: The best answer is B because 1NF primarily deals with eliminating repeating
groups of data and ensuring that each field contains only a single, atomic value.
Q4: Which of the following scenarios describes a table that violates Second Normal
Form (2NF)?
A. A table contains a column that is calculated from other columns in the same row
B. A table has a composite primary key, and a non-key attribute depends only on part of
that composite key
C. A table contains a foreign key that references a non-existent primary key in another
table
D. A table allows null values in a column that is designated as a primary key
Correct Answer: B
Rationale: This matches the rule that 2NF requires removing partial dependencies,
meaning all non-key attributes must rely on the entire primary key, not just a portion of it.
Q5: When moving from 2NF to 3NF (Third Normal Form), what specific type of
dependency must be removed?
A. Partial dependency
B. Functional dependency
C. Transitive dependency
D. Multivalued dependency
Correct Answer: C
Rationale: The best answer is C because 3NF is achieved by eliminating transitive
dependencies, where non-key attributes depend on other non-key attributes rather than
directly on the primary key.
Q6: A Student table contains columns: StudentID, Name, Major, and AdvisorName. If
AdvisorName is functionally dependent on Major (i.e., every Major has the same Advisor),
which Normal Form rule is being violated?
A. 1NF
B. 2NF
C. 3NF
D. BCNF
Correct Answer: C
Rationale: This choice is correct because AdvisorName depends on Major (a non-key
attribute) rather than directly on StudentID, which creates a transitive dependency
violating 3NF.
Q7: Which of the following statements accurately describes a Composite Key?
A. It is a single column that uniquely identifies a row due to a unique constraint
, B. It is a primary key consisting of two or more columns used together to uniquely
identify a record
C. It is a surrogate key generated automatically by the database system
D. It is a foreign key that links to multiple different parent tables
Correct Answer: B
Rationale: This query works because a Composite Key is defined as a key that utilizes
two or more columns to create a unique identifier for a row when a single column is
insufficient.
Q8: In an Entity-Relationship (ER) Diagram, what does the "Crow's Foot" notation at the
end of a relationship line typically signify?
A. A "one" side of the relationship
B. A "many" side of the relationship
C. An optional relationship
D. A mandatory relationship
Correct Answer: B
Rationale: The best answer is B because the crow's foot symbol is the standard notation
used to represent the "many" cardinality in data modeling diagrams.
Q9: You need to store data that describes a product with variable attributes like color,
size, and weight, where different products have different attributes. Which design issue
is most likely to arise if you put all these into a single wide table with many nullable
columns?
A. Data redundancy
B. Sparse data and excessive NULLs
C. Circular reference
D. Loss of primary key integrity
Correct Answer: B
Rationale: This choice is correct because using a single table for varying attributes
leads to many empty columns (NULLs) for rows that don't require those specific
attributes, creating a sparse and inefficient table structure.
Q10: Scenario: A vendor provides a raw spreadsheet of sales data that looks like this:
InvoiceID | Date | CustomerName | Item1 | Item2 | Item3 | TotalPrice. The data
for items is repeated across columns. You need to normalize this to 3NF. Which step is
correct?
A. Move CustomerName to a new table and link it using InvoiceID
B. Separate the items into a new LineItems table linked by InvoiceID, and separate
CustomerName into a Customers table linked by CustomerID
C. Simply delete the Item2 and Item3 columns to make the table flatter
D. Add a new primary key to the existing table without changing the column structure
