Step-by-Step Normalization
Start with a flat spreadsheet-style table and apply 1NF, 2NF, 3NF successively. Each step resolves a specific class of redundancy.
MySQL
Intermediate
5 min read
Normalizing a Table Step by Step
Example
-- Start: flat orders sheet
-- order_id, customer, email, product, qty, price, category
-- 1NF: ensure atomic values, add PK
-- 2NF: separate customers (email depends on customer not order)
-- 3NF: separate products and categories (category depends on product)
-- Result: orders, customers, products, categories, order_items tables Pro Tip
Work top-down: identify the main entity first, then extract related entities.