Database: Entity Relationship Diagram.

In today’s seminar we looked into a few database functions called ‘ERD’ Entity Relationship Diagrams. An ERD is a way of organizing and a graphical representation of entities and their relationships to each other through a logical structure of a database.

The original notation for ERD’s used rectangles to represent entities and diamonds to represent relationships, they can also be seen as IDEF1X or a Crow’s foot like the images we used in our seminar below.collection_erd-01

Entitiy – is the thing we want to store information, for example a person, place, thing.

Attributes – is the data we are going to collect for an entity.

Relationships – describes the relations between the entities

collection_erd-02

Below is an example of a Recipe ERD that Simon gave us as an example to show the entity relations and how the database works.

recipe_erd

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