DAT602 Blog 2

Today I did some learning about entity relation diagrams (ERD). ERD’s are a modelling type for database design. They display the relationships between entities within the systems scope using a variety of different symbols. We looked into crow’s foot notation (or IE notation) as the form that we are using for the assessment. Crows foot notation uses several different graphical symbols to represent the relationship types. Below we can see the different types of relationships.

This method was relatively easy to do as we had covered this in DAT502 last year. I did not have any problems remembering how to implement crows foot notation into an ERD. The only issue I faced was the planning of the entities within the database. I struggled to identify what was required in each table. To fix this issue, I went back to my planning and looked at what I could do to reduce the overall size of tables and remove redundancies. In doing this I was able to remove attributes from tables within the database to reduce the size of them. This was good for my learning as I was able to improve my understanding of how to create ERD’s