normalization: normalized

task.sql

@@ -1,33 +1,56 @@
--- Create database and tables
-
+DROP DATABASE IF EXISTS ShopDB;
 CREATE DATABASE ShopDB;
 USE ShopDB;
 
 CREATE TABLE Countries (
-    ID INT,
-    Name VARCHAR(50),
+    ID INT AUTO_INCREMENT,
+    Name VARCHAR(50) NOT NULL,
     PRIMARY KEY (ID)
 );
 
-CREATE TABLE ProductInventory (
-    ID INT,
-    ProductName VARCHAR(50),
-    WarehouseAmount INT,
-    WarehouseName VARCHAR(50),
-    WarehouseAddress VARCHAR(50), 
-    CountryID INT,
-	FOREIGN KEY (CountryID) REFERENCES Countries(ID) ON DELETE NO ACTION,
-    PRIMARY KEY (ID)
+CREATE TABLE Products(
+	ID INT AUTO_INCREMENT,
+	Name VARCHAR(50) NOT NULL,
+	PRIMARY KEY (ID)
+);
+
+CREATE TABLE Warehouses(
+	ID INT AUTO_INCREMENT,
+	Name VARCHAR(50) NOT NULL,
+	CountryID INT,
+	FOREIGN KEY (CountryID) REFERENCES Countries(ID) ON DELETE SET NULL,
+	WarehouseAddress VARCHAR(50),
+	PRIMARY KEY (ID)
+);
+CREATE INDEX idx_Warehouses_CountryID ON Warehouses(CountryID);
+
+
+CREATE TABLE ProductInventory(
+	ID INT AUTO_INCREMENT,
+	ProductID INT,
+	FOREIGN KEY (ProductID) REFERENCES Products(ID) ON DELETE SET NULL,
+	WarehouseAmount INT,
+	WarehouseID INT,
+	FOREIGN KEY (WarehouseID) REFERENCES Warehouses(ID) ON DELETE SET NULL,
+	PRIMARY KEY (ID)
 );
+CREATE INDEX idx_ProductInventory_ProductID ON ProductInventory(ProductID);
+CREATE INDEX idx_ProductInventory_WarehouseID ON ProductInventory(WarehouseID);
+
+INSERT INTO Countries (Name) VALUES ('Country1');
+SET @Country1ID = LAST_INSERT_ID();
+INSERT INTO Countries (Name) VALUES ('Country2');
+SET @Country2ID = LAST_INSERT_ID();
+
+INSERT INTO Products (Name) VALUES ('AwesomeProduct');
+SET @Product1ID = LAST_INSERT_ID();
+
+INSERT INTO Warehouses (Name, CountryID, WarehouseAddress) VALUES ('Warehouse-1', @Country1ID, 'City-1, Street-1');
+SET @Warehouse1ID = LAST_INSERT_ID();
+INSERT INTO Warehouses (Name, CountryID, WarehouseAddress) VALUES ('Warehouse-2', @Country2ID, 'City-2, Street-2');
+SET @Warehouse2ID = LAST_INSERT_ID();
 
--- Populate test data
-
-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 ProductInventory (ProductID, WarehouseAmount, WarehouseID) 
+VALUES
+(@Product1ID, 2, @Warehouse1ID),
+(@Product1ID, 5, @Warehouse2ID);