When designing a database,one of the candidate keys in a relation is selected as the ________.
A)composite key
B)primary key
C)foreign key
D)surrogate key

Question

Quizplus · Accepted Answer

The primary key is the key that is chosen as the unique identifier for each record in the relation. It must be unique, non-null, and should not change over time. This key is used to establish relationships with other tables through the use of foreign keys. A composite key is created by combining two or more attributes to form a unique identifier for a record. A foreign key is a field in one table that refers to the primary key in another table. A surrogate key is a system-generated unique identifier that is added to a table when a natural key is not available.

When Designing a Database,one of the Candidate Keys in a Relation