An ERD is an Entity Relationship Diagram. This type of diagram represents the relationships between different entities. Typically the diagram displays data and uses different conventions to describe the relationship between each data point. The two notations for the Entity relationship diagram are the Entity and the attribute which are typically described using adjectives. The entity in an Entity Relationship diagram is symbolized by a rectangle, the attributes are symbolized by an oval, and the relationship is symbolized by a diamond. The Crow’s foot database is represented using boxes to acknowledge the different entities and the relationship of the entities are placed inside the boxes versus the Chens database notation which is exemplified by a literal diagram which has different directions and ovals to represent the different entities and the relationship between them. The key aspects of an ERD relationship are the notations, the symbols and what the diagram represents.
Reader Interactions
Comments
Leave a Reply
You must be logged in to post a comment.
Hi Cassidy,
I found this to be a very insightful post! I think you described an ERD in a way that is easy to understand, while still hitting all of the important points. I believe that ERDs are extremely useful tools, especially for those in MIS. It is a way to organize information when creating or updating a database in a way that is simple to understand. Especially when creating a database, having everything mapped out will make it easy to go back and reflect on what could be improved upon. Also, if you were creating a new database and wanted to refer back to an old one that you had created, an ERD lays out all of that information for you. So, I think this diagram is an extremely useful tool when creating and updating databases.