Data modelling - Record
Primary key
(Primary key)
A value that uniquely identifies one record in a database table
What's it for?
Gives each database record one unique identifier so it can be referred to without confusion.
For example…
Each employee number is a primary key, so two people never share the same staff ID
CustomerID is the primary key in a customer table because every customer record has one unique value that identifies it
Think of it like…
A car registration number: even if two cars are the same make, model and colour, it identifies exactly which one you mean