database.sql completed.

database.sql

@@ -1,141 +1,80 @@
--- Restaurant Database Management System
---
--- Instructions:
--- 1. Create all required tables.
--- 2. Design appropriate PRIMARY KEY and FOREIGN KEY relationships.
--- 3. Add suitable constraints based on the requirements.
--- 4. Insert initial mock data.
--- 5. Insert at least 3 menu items.
--- 6. The script should be executable from start to finish without errors.
-
-
-
--- =======================================================
 -- USER TABLE
--- =======================================================
---
--- Represents customers using the system.
---
--- Required information:
--- - Unique identifier
--- - Username
--- - Password
--- - Email (optional)
---
--- Requirements:
--- - Each user must have a unique identifier.
--- - Usernames must be unique.
--- - Username and password are required.
--- - Passwords should not be stored in plain text.
---
--- CREATE TABLE ...
+CREATE TABLE users (
+    id SERIAL PRIMARY KEY,
+    username VARCHAR(50) UNIQUE NOT NULL,
+    password VARCHAR(255) NOT NULL,
+    email VARCHAR(100)
+);
 
-
-
--- =======================================================
 -- MENU ITEM TABLE
--- =======================================================
---
--- Represents available food and drink items.
---
--- Required information:
--- - Unique identifier
--- - Name
--- - Description (optional)
--- - Price
--- - Category (optional)
---
--- Requirements:
--- - Each menu item must have a unique identifier.
--- - Name is required.
--- - Price must always be positive.
---
--- CREATE TABLE ...
+CREATE TABLE menu_items (
+    id SERIAL PRIMARY KEY,
+    name VARCHAR(100) NOT NULL,
+    description TEXT,
+    price DECIMAL(10,2) NOT NULL CHECK (price > 0),
+    category VARCHAR(50)
+);
 
-
-
--- =======================================================
 -- ORDER TABLE
--- =======================================================
---
--- Represents orders placed by customers.
---
--- Required information:
--- - Unique identifier
--- - Reference to customer
--- - Creation date and time
--- - Total price
---
--- Requirements:
--- - Each order must belong to exactly one user.
--- - A user can have multiple orders.
--- - The relationship between User and Order must be implemented.
---
--- Note:
--- Avoid using reserved SQL keywords as table names.
--- Consider using a name such as "orders" or "customer_orders".
---
--- CREATE TABLE ...
+CREATE TABLE orders (
+    id SERIAL PRIMARY KEY,
+    user_id INT NOT NULL,
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    total_price DECIMAL(10, 2) NOT NULL DEFAULT 0.00,
+    CONSTRAINT fk_user_order FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+);
 
-
-
--- =======================================================
 -- ORDER DETAIL TABLE
--- =======================================================
---
--- Represents items inside an order.
---
--- Required information:
--- - Unique identifier
--- - Reference to an order
--- - Reference to a menu item
--- - Quantity
--- - Item price at purchase time
---
--- Requirements:
--- - Each detail record must belong to one order.
--- - Each detail record must reference one menu item.
--- - Quantity must always be greater than zero.
--- - Store the item's price at the moment of purchase.
---
--- CREATE TABLE ...
+CREATE TABLE order_details (
+    id SERIAL PRIMARY KEY,
+    order_id INT NOT NULL,
+    menu_item_id INT NOT NULL,
+    quantity INT NOT NULL CHECK (quantity>0),
+    price_at_purchase DECIMAL(10,2) NOT NULL,
+    CONSTRAINT fk_detail_order FOREIGN KEY (order_id) REFERENCES orders(id) ON DELETE CASCADE,
+    CONSTRAINT fk_detail_menu FOREIGN KEY (menu_item_id) REFERENCES menu_items(id)
+)
 
 
-
--- =======================================================
 -- INITIAL MENU DATA
--- =======================================================
---
--- Insert at least 3 food or drink items.
---
--- Example categories:
--- - Pizza
--- - Burger
--- - Pasta
--- - Drink
---
--- INSERT INTO ...
+INSERT INTO menu_items (name, description, price, category) VALUES
+('Cheeseburger', 'Juicy beef patty with cheddar cheese', 8.99, 'Food'),
+('Pepperoni Pizza', 'Classic pizza with pepperoni and mozzarella', 12.50, 'Food'),
+('Iced Latte', 'Espresso with cold milk and ice', 4.25, 'Drink');
 
 
-
--- =======================================================
 -- OPTIONAL TEST DATA
--- =======================================================
---
--- You may insert sample users and orders for testing.
--- This section is optional.
---
--- INSERT INTO ...
+INSERT INTO users (username, password, email) VALUES
+('mardin_dev', 'hashed_pass_123', 'mardin@example.com'),
+('sara_kh', 'hashed_pass_456', 'sara@example.com');
+
+INSERT INTO orders (user_id, total_price) VALUES
+(1, 21.49),
+(2, 4.25);
+
+INSERT INTO order_details (order_id, menu_item_id, quantity, price_at_purchase) VALUES
+(1, 1, 1, 8.99),
+(1, 2, 1, 12.50);
+
+INSERT INTO order_details (order_id, menu_item_id, quantity, price_at_purchase) VALUES
+(2, 3, 1, 4.25);
 
 
-
--- =======================================================
 -- VERIFICATION QUERIES
--- =======================================================
---
--- Uncomment these queries to verify your database.
---
--- SELECT * FROM ...;
--- SELECT * FROM ...;
--- SELECT * FROM ...;
--- SELECT * FROM ...;
+SELECT * FROM users;
+SELECT * FROM menu_items;
+SELECT * FROM orders;
+SELECT * FROM order_details;
+
+SELECT
+    o.id AS order_number,
+    u.username AS customer,
+    m.name AS food_item,
+    od.quantity,
+    od.price_at_purchase,
+    (od.quantity * od.price_at_purchase) AS subtotal,
+    o.created_at
+FROM orders o
+         JOIN users u ON o.user_id = u.id
+         JOIN order_details od ON od.order_id = o.id
+         JOIN menu_items m ON od.menu_item_id = m.id;