Chapter 4, Problem 17RQ

Explanation of Solution

Cardinality:

Connecting lines among the entities will illustrate the relationships of entities in the ER diagram.

• “Cardinality” states that how many occurrences of an entity relate to one occurrence of other entity.

Crow’s Foot symbols and its cardinality:

The following table illustrates the different connectivity and participation combinations which are maintained by the Crow’s Foot notation:

Notation	Cardinality	Description
	(0,N)	Zero or more instances
	(1,N)	One or more instances
	(1,1)	One instance
	(0,1)	Zero or one instance

Cardinalities for given ERD:

The following figure illustrates the cardinalities for each relationship in given ER diagram: