Question

What is a primary key?​

Answer 1

Answer:

A primary key is either an existing table column or a column that is specifically generated by the database according to a defined sequence. For example, students are routinely assigned unique identification (ID) numbers, and all adults receive government-assigned and uniquely-identifiable Social Security numbers.

Explanation:

Answer 2

In the relational model of database,a primary key is a specific choice of a minimal set of attributes that uniquely specific a tuple in a relation. informally, a prime key in "which attributes identify a record", and in simple cases are simply

a single attributes :a unique I'd.