Several years ago, when I first started working with databases, I was lucky enough to work under a manager that believed in the value of Entity-Relationship Diagrams – better known as ERDs.
For those of you not familiar with ERDs, they show the relationships of entity sets stored in a database. In other words, they show how each table is related to another table (if they are related at all). They can be simple, as shown below:
Or the can be rather complex, like the following:
ERDs are truly great for showing everyone – and reminding yourself – how you can get data from one table when you also need data from another.
Just think about it – no more need to set down with a new developer and explain how each and every table connects to another table. All you’ll truly have to do is give them one file and make sure that they know how to read one of these diagrams.
Next time, we’ll review how to set up an ERD and what is required to get one set up.