Question

Which of the following attributes would most likely be a primary key?

A. supplier name
B. supplier number
C. supplier zip code
D. supplier account balance

Answer 1

The supplier number is the best choice for a primary key since it is a unique identifier for each supplier and meets the primary key criteria of uniqueness and not allowing null values.

Step-by-step explanation:

In databases, a primary key is a specific choice of a minimal set of attributes (columns) that uniquely specify a tuple (row) in a relation (table). A primary key’s main features are that it must contain unique values, and it cannot contain null values. Considering these constraints, the best attribute to use as a primary key would be supplier number because it is a unique identifier for each supplier. Other attributes such as supplier name, supplier zip code, and supplier account balance can have duplicates or may change over time, which disqualifies them as good primary keys.