The three paradigms of the database
1. 1NF fields are indivisible and atomic.
Take orders for example.
2. 2NF must satisfy the first normal form to satisfy the second normal form. A table can only describe one transaction, and the non-primary key attributes must completely depend on the primary key attributes.
3. To satisfy 3NF, 2NF must be satisfied first. Each column has a relationship with the primary key, and there is no transitive dependency. Any non-primary property does not depend on other non-primary properties.