Week 4 notes

What is Process Modeling?

A graphical representation of processes that capture, manipulate, store, and distribute data.

What is the purpose of an Entity Relationship Diagram (ERD)?

Used to model relational databases and define business logic.

What do Entities represent in ERDs?

Real-world objects, such as Employee, Car, or House.

What is a Primary Key in an ERD?

An attribute that uniquely identifies an entity and should be stable and unique.

What is the relationship degree of Unary?

An entity is related to itself, such as 'Employee manages Employee'.

What does Cardinality define in relationships?

How many instances of one entity relate to another.

What does a 1:M cardinality imply?

One entity relates to multiple instances of another entity, such as a customer placing multiple orders.

What are Multi-Valued Attributes?

Attributes that have multiple values for a single entity, like an 'Employee' having multiple skills.

What is a key benefit of using Entity Relationship Diagrams?

Provides a conceptual data model and helps in understanding business rules.

What should be done to Multi-Valued Attributes in ERDs?

Convert them into a new entity.

What are database business rules?

Constraints and policies that govern how a database operates.