In an entity-relationship diagram,a ________ on a line means that the entity is optional.
A)vertical bar
B)crow's foot
C)small oval
D)key

Question

Quizplus · Accepted Answer

A small oval or circle on a line in an entity-relationship diagram indicates that the relationship is optional or may not exist. This means that the entity on the other end of the line may or may not have a connection with the entity in question. In contrast, a vertical bar indicates a mandatory relationship, while a crow's foot denotes a one-to-many relationship between two entities. Keys, on the other hand, are used to uniquely identify entities in a diagram.

In an Entity-Relationship Diagram,a ________ on a Line Means That