Week 3 Entity Relationship Diagrams

Question 1

What are Attributes?

Answer 1

Attributes are the properties of an entity. E.g. Price, Shr Code, Quantity.

Question 2

What is an Entity?

Answer 2

An entity is a thing which is used to become a table or a database. E.g. Boy, Girl, Customer

Question 3

What are Identifiers?

Answer 3

Every instance of an entity, like a row or a table must be labelled. These labels are called ‘keys’.

Question 4

What are the 3 types of ERD relationships?

Answer 4

1) One to Many
2) Many to Many
3) Self-Referencing