Types of Relationship Combinations

Entities are often involved in a variety of relationships. Optional relationships are often affected by the existence of another relationship. Clarify the nature of two or more relationships concerned with a particular entity by one of the following combinations: inclusive OR (either or both)

exclusive OR (either, but not both)

AND (both must exist).

Inclusive OR An inclusive OR relationship indicates that entity A is related to either entity B or entity C or both B and C. Exclusive OR An exclusive OR relationship indicates that entity A is related to either entity B or entity C but not both B and C. AND An AND relationship indicates that entity A is related to both entity B and entity C.