Question

why do we need a primary key ? ​

Answer 1

Answer:

The main purpose of primary key is to identify the uniqueness of a row, where as unique key is to prevent the duplicates, following are the main difference between primary key and unique key. Primary Key : There can only be one primary key for a table. The primary key consists of one or more columns.

Explanation:

please mark me as brainlist

Answer 2

Answer:

for the main propuse or it is special so we call primary key