Question

define primary key. What are the two requisites for a field to become a primary key.

Answer 1

Answer:

A primary key is a special relational database table column (or combination of columns) designated to uniquely identify all table record

Explanation:

A primary key is a special relational database table column (or combination of columns) designated to uniquely identify all table record

Answer 2

A primary key's main features are:

• It must contain a unique value for each row of data.

• It cannot contain null values.

•Every row must have a primary key value.