Primary Key

Why is the choice of primary key important and are three characteristics of an ideal primary key?

kh_trnh
Profile Answers by kh_trnh Questions by kh_trnh
Jul 18th, 2008
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chaitra murthy
Profile Answers by chaitra murthy

Jan 16th, 2009

Primary key will let the retrieval operation to be fast.
It will not allow you to insert duplicate and null values.
It is used to uniquely identify a row in a table.

sanit kale

Apr 23rd, 2014

The PRIMARY KEY constraint uniquely identifies each record in a database table.

Primary keys must contain unique values.

A primary key column cannot contain NULL values.

Each table should have a primary key, and each table can have only ONE primary key.