WGU D427 Database Management Applications
Exam Practice Questions with Verified Answers
1: What is a primary key in a database? --- correct answer ---
A primary key is a unique identifier for a record in a database table,
ensuring that no two records have the same key value.
2: Explain the concept of a foreign key. --- correct answer ---
A foreign key is a field (or collection of fields) in one table that uniquely
identifies a row of another table, creating a relationship between the two
tables.
3: What is normalization in database management? --- correct answer ---
Normalization is the process of organizing data in a database to reduce
redundancy and improve data integrity.
4: Describe the first normal form (1NF). --- correct answer ---
A table is in the first normal form if all its attributes contain only atomic
(indivisible) values and each record is unique.
,5: What is SQL and what is it used for? --- correct answer ---
SQL (Structured Query Language) is a programming language used for
managing and manipulating relational databases.
6: Name the four basic operations of CRUD. --- correct answer ---
The four basic operations of CRUD are Create, Read, Update, and Delete.
7: What is a JOIN operation in SQL? --- correct answer ---
A JOIN operation in SQL is used to combine rows from two or more tables
based on a related column between them.
8: Explain the difference between INNER JOIN and OUTER JOIN. --- correct
answer ---
INNER JOIN returns only the rows with matching values in both tables,
whereas OUTER JOIN returns all rows from one table and the matched rows
from the other, filling in NULLs for unmatched rows.
, 9: What is a database index and why is it important? --- correct answer ---
A database index is a data structure that improves the speed of data
retrieval operations on a database table at the cost of additional writes and
storage space.
10: Define a transaction in the context of databases. --- correct answer ---
A transaction is a sequence of database operations that are treated as a
single logical unit of work, ensuring data integrity through ACID properties.
11: What are the ACID properties of a transaction? --- correct answer ---
The ACID properties are Atomicity, Consistency, Isolation, and Durability,
which ensure reliable processing of database transactions.
12: What is the purpose of a database trigger? --- correct answer ---
A database trigger is a procedural code that is automatically executed in
response to certain events on a particular table or view.
13: Explain the concept of a stored procedure. --- correct answer ---
Exam Practice Questions with Verified Answers
1: What is a primary key in a database? --- correct answer ---
A primary key is a unique identifier for a record in a database table,
ensuring that no two records have the same key value.
2: Explain the concept of a foreign key. --- correct answer ---
A foreign key is a field (or collection of fields) in one table that uniquely
identifies a row of another table, creating a relationship between the two
tables.
3: What is normalization in database management? --- correct answer ---
Normalization is the process of organizing data in a database to reduce
redundancy and improve data integrity.
4: Describe the first normal form (1NF). --- correct answer ---
A table is in the first normal form if all its attributes contain only atomic
(indivisible) values and each record is unique.
,5: What is SQL and what is it used for? --- correct answer ---
SQL (Structured Query Language) is a programming language used for
managing and manipulating relational databases.
6: Name the four basic operations of CRUD. --- correct answer ---
The four basic operations of CRUD are Create, Read, Update, and Delete.
7: What is a JOIN operation in SQL? --- correct answer ---
A JOIN operation in SQL is used to combine rows from two or more tables
based on a related column between them.
8: Explain the difference between INNER JOIN and OUTER JOIN. --- correct
answer ---
INNER JOIN returns only the rows with matching values in both tables,
whereas OUTER JOIN returns all rows from one table and the matched rows
from the other, filling in NULLs for unmatched rows.
, 9: What is a database index and why is it important? --- correct answer ---
A database index is a data structure that improves the speed of data
retrieval operations on a database table at the cost of additional writes and
storage space.
10: Define a transaction in the context of databases. --- correct answer ---
A transaction is a sequence of database operations that are treated as a
single logical unit of work, ensuring data integrity through ACID properties.
11: What are the ACID properties of a transaction? --- correct answer ---
The ACID properties are Atomicity, Consistency, Isolation, and Durability,
which ensure reliable processing of database transactions.
12: What is the purpose of a database trigger? --- correct answer ---
A database trigger is a procedural code that is automatically executed in
response to certain events on a particular table or view.
13: Explain the concept of a stored procedure. --- correct answer ---
