An entity and its 1:M unary relationship are mapped as one relation.

Question

Quizplus · Accepted Answer

In a 1:M unary relationship, the entity on the "one" side is connected to multiple instances of itself on the "many" side. This can be represented by adding a foreign key in the "many" side that references the primary key of the "one" side. Since this relationship can be represented within a single relation, the entity and its 1:M unary relationship are mapped as one relation.

An Entity and Its 1:M Unary Relationship Are Mapped as One