Entity Relationship Diagrams (ERDs)

We have already noted that designing databases can be a very complex activity. Entity Relationship Diagrams (ERDs) are an important conceptual modeling tool which can assist in developing effective and efficient databases. Initially, many students do not appreciate how important conceptual modeling tolls are, and only appreciate them after they have put together their first database without them, only to realize that they must redo the entire database.

In this section, will will overview the basic components of ERDs, and use a ERD to establish a database for a (somewhat) involved semantically constrained problem.