CSS - PMS - CCE - PCS - Basic Computing
Database Basics
What is the main purpose of an Entity-Relationship Diagram?
A. To visually model entities, attributes, and relationships
B. To repair hardware
C. To create passwords
D. To print only one table
Correct Answer: A
An ERD helps design and communicate the logical structure of a database.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
In Crow's Foot notation, the crow's-foot symbol represents:
A. Many
B. One
C. Zero only
D. A primary key
Correct Answer: A
The three-pronged crow's-foot symbol indicates the 'many' side of a relationship.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
In many ER diagrams, a primary key attribute is shown by:
A. Underlining the attribute name
B. Deleting the attribute
C. Writing it in lowercase only
D. Adding a page number
Correct Answer: A
A common ERD convention is to underline attributes that form the primary key.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
An entity that cannot be uniquely identified without another entity is called a:
A. Weak entity
B. Strong entity
C. Independent entity
D. Database view
Correct Answer: A
A weak entity depends on a related strong entity for identification.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
An attribute calculated from other attributes is called a:
A. Derived attribute
B. Composite key
C. Primary attribute
D. Foreign key
Correct Answer: A
A derived attribute is calculated, such as Age derived from DateOfBirth.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
An attribute that may contain several values for one entity is called:
A. Multivalued attribute
B. Primary attribute
C. Foreign attribute
D. Atomic attribute
Correct Answer: A
A multivalued attribute can hold more than one value, such as multiple phone numbers.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
An attribute that can be divided into smaller meaningful parts is called:
A. Composite attribute
B. Derived attribute
C. Single-valued attribute
D. Foreign attribute
Correct Answer: A
A composite attribute can be broken down, such as Address into Street, City, and PostalCode.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
An association between two or more entities is called a:
A. Relationship
B. Data type
C. Constraint
D. Report
Correct Answer: A
A relationship represents how entities are connected to each other.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
A property that describes an entity is called an:
A. Attribute
B. Transaction
C. Procedure
D. Backup
Correct Answer: A
An attribute is a characteristic of an entity, such as StudentName or DateOfBirth.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
In ER modeling, an object or concept about which data is stored is called an:
A. Entity
B. Attribute
C. Query
D. Index
Correct Answer: A
An entity is a person, place, object, event, or concept represented in a database.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
The number of possible records participating in a relationship is called:
A. Cardinality
B. Redundancy
C. Validation
D. Aggregation
Correct Answer: A
Cardinality describes whether a relationship is one-to-one, one-to-many, or many-to-many.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
A many-to-many relationship is normally implemented using a:
A. Junction table
B. Single text field
C. Printed report
D. Backup file
Correct Answer: A
A junction or bridge table stores the keys of both related tables and resolves the many-to-many relationship.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
A relationship in which many students take many courses is:
A. One-to-one
B. One-to-many
C. Many-to-many
D. Unary only
Correct Answer: C
Many students can take many courses, creating a many-to-many relationship.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
A relationship in which one department has many employees is:
A. One-to-one
B. One-to-many
C. Many-to-many
D. Zero-to-zero
Correct Answer: B
One department can be associated with many employees, while each employee belongs to one department.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
A relationship in which one record in Table A relates to one record in Table B is:
A. One-to-one
B. One-to-many
C. Many-to-many
D. No relationship
Correct Answer: A
A one-to-one relationship connects each record on one side with at most one record on the other side.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
A child record that refers to a missing parent record is called an:
A. Orphan record
B. Master record
C. Primary record
D. Index record
Correct Answer: A
An orphan record contains a foreign-key reference for which no matching parent record exists.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
What does ON DELETE CASCADE do?
A. Deletes related child rows when the parent row is deleted
B. Deletes the entire database server
C. Prevents all queries
D. Creates a backup automatically
Correct Answer: A
ON DELETE CASCADE automatically removes dependent child records when the referenced parent record is deleted.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
A restriction that limits the valid values of an attribute is known as a:
A. Domain constraint
B. Join condition
C. Report filter
D. Backup rule
Correct Answer: A
A domain constraint limits values according to data type, range, format, or an allowed set.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
Which constraint automatically supplies a value when none is provided?
A. DEFAULT
B. PRIMARY KEY
C. FOREIGN KEY
D. HAVING
Correct Answer: A
The DEFAULT constraint inserts a predefined value when an explicit value is not supplied.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
Which constraint checks whether a value satisfies a specified condition?
A. CHECK
B. DROP
C. SELECT
D. UNION
Correct Answer: A
A CHECK constraint allows only values that satisfy a defined logical condition.