WorksheetsDatabase Concepts Quiz
Total questions: 30
Worksheet time: 15mins
What is the purpose of data abstraction in a database system?
To display all data to the user
To improve hardware speed
To hide complex details of data storage from the user
To encrypt user passwords
Which of the following best defines an instance in a database?
The physical location of a database file
A snapshot of the data in the database at a particular time
A type of SQL query
A data entry form
What is a schema in database design?
A column of data in a table
The overall logical structure of a database
A security password
A user’s record
Which of the following database structures uses a tree-like format to store data?
Hierarchical database
Network database
Relational database
Graph database
What distinguishes a network database structure?
Uses a linear data format
Allows many-to-many relationships using graph structure
Stores data only in tables
Uses no indexing
Which structure is most commonly used in modern systems for storing and querying data?
Network structure
Relational structure
Tree-based structure
Sequential file structure
Which of the following is a characteristic of object-oriented database structures?
Stores data only in rows and columns
Uses classes and objects similar to programming languages
Does not support inheritance
Does not store methods with data
Which structure is best suited for real-time GPS navigation systems using unstructured data?
Hierarchical
Relational
NoSQL
Flat file
Which SQL statement is used to add new records to a table?
SELECT
DELETE
UPDATE
INSERT
Which SQL operation is used to retrieve data from a database?
INSERT
DELETE
SELECT
MODIFY
Which SQL keyword is used to remove existing records from a table?
DELETE
INSERT
VIEW
ADD
What does the SQL UPDATE command do?
Creates a new database
Deletes existing data
Modifies existing data
Renames a table
Which SQL command would you use to change a student's course from “ICT Level 5” to “Software Engineering”?
SELECT
UPDATE
INSERT
DELETE
Which of the following SQL statements retrieves all records from a table named Students?
SELECT * IN Students
VIEW ALL FROM Students
SELECT * FROM Students
GET ALL Students
What does WHERE clause do in an SQL SELECT statement?
Deletes specific data
Filters records based on conditions
Creates a new column
Sorts the data by date
Which data model represents entities and their relationships?
Flat File Model
Network Model
ER Model (Entity Relationship)
Tabular Model
In an ER model, what does an “entity” typically represent?
A file system
A real-world object like a student or course
A field in a record
A computer program
Which symbol is commonly used to represent a relationship in an ER diagram?
Circle
Triangle
Diamond
Square
What is a key characteristic of the relational model?
Uses hierarchical indexes
Contains only unstructured data
Organizes data into rows and columns
Uses object inheritance
Which model organizes data using parent-child relationships?
Hierarchical model
Network model
Relational model
Object model
In a network model, a child can:
Have only one parent
Have multiple parent records
Not have any parents
Only be linked to leaf nodes
What is the main focus of the relational model?
Class diagrams
Data stored in tables with relationships
Binary data trees
Memory indexing
In a relational database, what uniquely identifies a record?
Column name
Primary key
Data type
File path
In the ER model, a relationship between 'Teacher' and 'Class' would be represented as:
Attribute
Primary key
Connection line with diamond
Field
Which SQL statement would you use to remove a student from a database?
UPDATE
DELETE
INSERT
SELECT
Which of the following best describes data abstraction?
The process of hiding internal database complexities from users
Writing user interfaces
Making backups
Encrypting data
In relational databases, what is a 'tuple'?
A type of index
A column of data
A row in a table
A SQL operator
What does normalization help to achieve?
Data duplication
Unstructured storage
Reduced redundancy and improved integrity
File compression
Which database structure allows data to be accessed through navigational paths?
Relational
Network
Object
Tabular
What is the benefit of using an ER model before creating a physical database?
Helps with software coding
Helps design logical relationships and structure
Improves file size
Adds storage space
