Skip to content

Normalize the database ShopDB #159

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
AndS9 wants to merge 3 commits into
base: main
Choose a base branch
from
Open

Normalize the database ShopDB #159

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
20f3551
Normalize the database ShopDB
AndS9 Mar 28, 2026
d2911d1
Fixes 1.0.1
AndS9 Mar 28, 2026
faf9a90
Fixes 1.0.2
AndS9 Mar 28, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
40 changes: 29 additions & 11 deletions task.sql
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@
-- Create database and tables

DROP DATABASE IF EXISTS ShopDB;
CREATE DATABASE ShopDB;
USE ShopDB;

Expand All @@ -9,25 +10,42 @@ CREATE TABLE Countries (
PRIMARY KEY (ID)
);

CREATE TABLE ProductInventory (
CREATE TABLE Warehouses (
ID INT,
Name VARCHAR(50),
Address VARCHAR(100),
CountryID INT,
FOREIGN KEY (CountryID) REFERENCES Countries(ID) ON DELETE NO ACTION,
PRIMARY KEY (ID)
);
CREATE TABLE Products (
ID INT,
ProductName VARCHAR(50),
PRIMARY KEY (ID)
);

CREATE TABLE ProductInventory (
ID INT,
ProductID INT,
WarehouseAmount INT,
WarehouseName VARCHAR(50),
WarehouseAddress VARCHAR(50),
CountryID INT,
FOREIGN KEY (CountryID) REFERENCES Countries(ID) ON DELETE NO ACTION,
WarehouseID INT,
Copy link
Copy Markdown

@mateacademy-ai-mentor mateacademy-ai-mentor Mar 28, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

While this table might seem to be in 3NF with ID as the primary key, it doesn't fully meet the goals of normalization. The ProductName column creates data redundancy (e.g., 'AwesomeProduct' is repeated), which can lead to update, insertion, and deletion anomalies. A better 3NF design would involve creating a separate Products table for product information and using a ProductID foreign key in this table instead of ProductName.

FOREIGN KEY (WarehouseID) REFERENCES Warehouses(ID) ON DELETE CASCADE,
FOREIGN KEY (ProductID) REFERENCES Products(ID) ON DELETE SET NULL,
PRIMARY KEY (ID)
);

-- Populate test data

INSERT INTO Products(ID, ProductName)
VALUES (1, 'AwesomeProduct');
INSERT INTO Countries (ID,Name)
VALUES (1, 'Country1');
INSERT INTO Countries (ID,Name)
VALUES (2, 'Country2');

INSERT INTO ProductInventory (ID,ProductName,WarehouseAmount,WarehouseName,WarehouseAddress,CountryID)
VALUES (1, 'AwersomeProduct', 2, 'Warehouse-1', 'City-1, Street-1',1);
INSERT INTO ProductInventory (ID,ProductName,WarehouseAmount,WarehouseName,WarehouseAddress,CountryID)
VALUES (2, 'AwersomeProduct', 5, 'Warehouse-2', 'City-2, Street-2',2);
INSERT INTO Warehouses(ID, Name, Address, CountryID)
VALUES (1,'Warehouse-1', 'City-1, Street-1', 1);
INSERT INTO Warehouses(ID, Name, Address, CountryID)
VALUES (2, 'Warehouse-2', 'City-2, Street-2', 2);
INSERT INTO ProductInventory(ID,ProductID,WarehouseAmount,WarehouseID)
VALUES (1, 1, 2, 1);
INSERT INTO ProductInventory(ID,ProductID,WarehouseAmount,WarehouseID)
VALUES (2, 1, 5,2);
Loading