Worked Walkthrough: Normalize an Order Entry Table to 3NF
Normalize a mixed order-entry table into a cleaner transactional design that reduces anomalies.
The source table order_entry_flat stores customer name and address, order date and payment status, product description and category, plus quantity and unit price, all on each row. Decompose the table so each non-key attribute depends on the key of its own entity or relationship, not on some other part of the row. A common trap is keeping product description or customer address on every line “for convenience,” then trying to update those repeated values consistently later. Identify the entities and relationships Customer, Order, Product, and Order Line are distinct subjects with different keys. This reveals that the current row is…
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