22+ Design Entity Relationship Model Example Download Zip Pictures. In the following er diagram we have two entities student. An entity is represented as rectangle in an er diagram.
This is a variant (actually a predecessor) of object modeling (eg uml or the first modeling step is to identify the entities.
Start studying entity relationship (er) model. The following case study describes the data the data held on each branch is the branch address (street, city, state, and zip code) and telephone number. Department controls projects project has name. By defining the entities, their attributes, and showing the relationships between them, an er diagram illustrates the logical er diagrams are used to sketch out the design of a database.