Entity Relationship Modeling

What defines an entity in database design?

• A physical object only
• A category of object, person, event, or thing of interest about which data needs to be recorded
• A database table structure
• A primary key identifier

In the a standard relational database model, what represents a unique identifier for each entity?

• Foreign Key
• Surname
• Title
• Primary key

Why can't many-to-many relationships be directly represented in database tables?

• They are too complex
• Database systems don't support them
• They require multiple fields which become impractical
• They always need a single unconnected table

What is a foreign key's primary function?

• To create a join between two tables
• To create decorative links between tables
• To replace primary keys
• To generate random identifiers

In a one-to-many relationship, where does the foreign key typically reside?

• In the 'one' side table
• In a separate linking table
• It doesn't matter
• In the 'many' side table

What advantage does a composite primary key offer?

• It makes tables more complex
• It saves space and simplifies table structure
• It increases database size
• It allows unlimited relationships

What are the three possible relationship types between entities?

• Linear, Circular, Diagonal
• Primary, Secondary, Tertiary
• One-to-one, One-to-many, Many-to-many
• Strong, Weak, Neutral

In the RevisionSubs example, what entities were initially considered?

• Student, Teacher, Course
• User, Order, Payment
• Customer, Product, Subscription
• Client, Service, Contract

What convention was used for naming tables in the example?

• camelCase
• Prefixed with 'tbl'
• PascalCase
• Lowercase with underscores

What defines an attribute in an entity description?

• A unique identifier
• A relationship between entities
• A column or field containing specific data about the entity
• A primary key