Candidate key in SQL Server

Question

Hi friends......... I know concept of primary key and foriegn key but I want to know concept of candidate key in Sql Server ? Please explain candidate key with an example ? Thanks........

Vulpes · Answer

A candidate key is any column or combination of columns which provides a unique result and could therefore be a primary key. A primary key is the candidate key which is actually chosen for that purpose. There can of course only be one primary key but there could be multiple candidate keys.