1. Entity Classes and Attributes
Entity Class are represented by rectangles
Attributes are represented by ovals
Key attribute is represented by an underline
Multivalued attributes is represented with an oval with a double border
Derived attribute is represented with an oval dashed border -- Example the AGE from current -
birth
Composite attribute is represented with an oval that connects to additional ovals
Relationship Types and Constraints
A relationship type is represented by a diamond and two connecting lines. The name of the
relationship is shown inside the diamond. Reading the diagram from left to right to yields "a store
owns a video"..
The name of the relationship type is a verb or verb phrase that describes the relationship.
The alternate relationship name IsOwnedBy is the name of the relationship type when reading the
other direction.