Representing a unary one-to-many relationship in a relational database ____.
A) requires the creation of an additional relation
B) requires adding a new column, the domain of values of which is the same as the relation's primary key
C) requires adding a new column, the domain of values of which is the same as the primary key of another relation in the database
D) requires modifying the primary key of the relation
E) requires replacing the primary key of the relation with an alternate key

Question

Quizplus · Accepted Answer

CIn a unary one-to-many relationship, where an entity is related to multiple instances of itself, two approaches can be used. Option B involves adding a new column to the existing relation, where this column's values reference the primary key of the same relation, effectively creating a parent-child relationship within the same table. Option C involves adding a new column whose values are the same as the primary key of another relation, which is a general approach for representing relationships between different tables but can also apply within the same table if conceptualized as such. This allows for the representation of hierarchical or recursive relationships within a single entity type.

Representing a Unary One-To-Many Relationship in a Relational Database ____