Normalization

Denormalized form

Below is an example of a denormalized table representing all information in one large relation. Notice that several columns contain multiple values (images, colors, addresses, products, etc.), which violates First Normal Form.

order_num	client_name	client_email	delivery_address	product_code(s)	product(s)	product_images	product_colors	product_price	order_quantity	store_ID	store_name	store_rating	employee	store_owner	order_status	payment	discount	review-comment	order_rating	request	request_problem	report_profit	monthly_profit	order_total	sales_trend
0012025000001	Marija Kostova	marija@…	st.Turisticka 5, Bitola	00100001	Handmade Wooden Chair	chair.jpg	Brown	700	1	001	WoodCraft Skopje	4.6	Antonio Trajkovski	Marko Petrovski	Delivered	Cash	0.04	Great quality, slightly late delivery	4.5	001112025001	Late delivery	125000	12500	700	Increasing
0022025000001	Ivan Stojanov	ivan@…	st.Partizanska 10, Skopje	00200002	Decorative Wall Hanging	wall_hanging.jpg	White & Pink, Black & Gold, Orange-Green-Purple	199	2	002	Fox Crochets	4.8	Sara Vaneva	Sara Vaneva	Placed Order	Credit Card	0.0	Excellent craftsmanship	5.0	002122025001	Military Discount	98000	8000	350	Stable
0022025000002	Ivan Stojanov	ivan@…	st.Partizanska 10, Skopje	00200001	Heart Crochet	crochet-heart-red.jpg, crochet-heart-blue.jpg	Blue, Red, Yellow, Green	150	3	002	Fox Crochets	4.8	Sara Vaneva	Sara Vaneva	Packaging	PayPal	0.0	Beautiful handmade product	5.0	—	—	98000	8000	50	Stable
0012025000002	Antoneta Mariovska	mariovskaantoneta@…	st.32 4, s.Cucer-Sandevo	00100001,00200001	Wooden Chair, Heart Crochet	chair.jpg, crochet-heart-red.jpg	Brown, Blue, Red	850	2	001,002	WoodCraft Skopje & Fox Crochets	4.0	Antonio Trajkovski	Marko Petrovski	Packaging	Credit Card	0.05	Very satisfied	5.0	003122025001	Packaging question	223000	20500	750	Increasing
0022025000003	Ivan Stojanov	ivan@…	st.Partizanska 10, Skopje	00200002	Decorative Wall Hanging	wall_hanging.jpg	Black & Gold	199	1	002	Fox Crochets	4.8	Sara Vaneva	Sara Vaneva	Placed Order	Credit Card	0.02	Wonderful decoration	5.0	004122025001	Shipping question	98000	8000	350	Stable

Problems with the Denormalized Table

This table contains several issues:

• Multiple products may appear in one order.
• A product may have multiple colors.
• A product may have multiple images.
• Client information repeats for every order.
• Store information repeats for every product sold.
• Employee and boss information repeats.
• Reports and profits repeat for every order.
• There are repeating groups, making updates difficult.
• Insertion, deletion, and update anomalies may occur.

Because of these problems, the table is not in First Normal Form.

First Normal Form(1NF)

To achieve 1NF:

• Every column must contain atomic values.
• No repeating groups.
• No lists inside cells.
• Every row represents exactly one occurrence.

Instead of storing several colors or images in one field, each value gets its own row.

CLIENT

client_id	First Name	Last Name	Email	|
1	Ivan	Stojanov	ivan@…
2	Marija	Kostova	marija@…
3	Antoneta	Mariovska	mariovskaantoneta@…