SQL Super Key
A Super Key is a set of one or more columns that can uniquely identify each record (row) in a table.
In simple words:
👉 Any column or combination of columns that makes every row unique is called a Super Key.
A Super Key may contain extra columns that are not necessary for uniqueness.
This is the main difference between Super Key and Candidate Key.
Relationship Between Keys
Super Key ↓ Candidate Key ↓ Primary Key Explanation: Super Key → Any unique identifier Candidate Key → Minimal Super Key Primary Key → Selected Candidate Key
Simple Definition
👉 A Super Key is any column or group of columns that can uniquely identify each row in a table.
It may include extra attributes.