A primary key is a column used to uniquely identify each record in a table.
Every table should have a primary key.
Primary keys help differentiate one record from another.
Primary key values must be unique.
They cannot contain duplicate or null values.
This ensures every row can be identified clearly.
A primary key is usually created on an id column.
This column acts as the main reference for the table.
Other tables can use this key to create relationships.
Primary keys improve data consistency and performance.
They are required when creating relationships between tables.
Most database designs start by defining primary keys.
Using primary keys is a standard practice in database design.
Almost all real-world databases rely on primary keys.
Understanding primary keys is essential for advanced SQL concepts.