Question

what is the use of primary key

Answer 1

A primary key, also called a primary keyword, is a key in a relationaldatabase that is unique for each record. It is a unique identifier, such as a driver license number, telephone number (including area code), or vehicle identification number (VIN). Arelational database must always have one and only one primary key.

Answer 2

Use of Primary Key is as below :-

A Primary Key is a sort of check on the table that uniquely identifies each record in a table .
It does not contain any duplicate data . A table can only have One Primary Key . The value In the Primary Key field is different for every record and thus helps in uniquely identifying the records ....