Basics of An ER Diagram

by Jamal A
The article I read talks about how important it is to create an ER Diagram, and how it should be
the starting point for software development projects. According to the article, “The very first step to
create an ER Diagram is to identify the nouns (entities)”.  For example: Company, Employee, and Project.
The article explained how ER Diagram “transmits a lot of information with a very short notation”.
There are some important signs to remember when creating an ER Diagram, For example:
Zero through Many (crow’s feet, O), One through Many (crow’s feet, dash), One and Only
One (dash, dash), Zero or One (dash, O). These are some of the symbols used when creating an ER Diagram.
The article also over viewed the three relationship types and explained how they are used.
These are: One to Many, Many to Many, and One to One. It went in further detail about these relationships
and explained which the most common relationship types are.

I think this article is related to the class because it talks about the important aspects of an ER Diagram.
I learned a lot from this article. Because it’s not only describes the basic of the ER Diagram, but also it
goes in detail about the relationships and how they should be used.

Lee Richardson. (2007). An Entity Relationship Diagram Example .
Http://rapidapplicationdevelopment.blogspot.com/20 07/06/entity-relationship-diagram-example.html.
Retrieved 01/22/2012 from http://rapidapplicationdevelopment.blogspot.com.