Restaurant Database Management System

database.sql

@@ -1,141 +1,85 @@
--- 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) NOT NULL UNIQUE,
+                       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 NUMERIC(10,2) NOT NULL CHECK (price > 0),
+                            category VARCHAR(50)
+);
 
 -- =======================================================
--- ORDER TABLE
+-- ORDERS 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 NUMERIC(10,2) NOT NULL DEFAULT 0,
 
+                        CONSTRAINT fk_orders_user
+                            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 NUMERIC(10,2) NOT NULL,
 
+                               CONSTRAINT fk_order_details_order
+                                   FOREIGN KEY (order_id)
+                                       REFERENCES orders(id)
+                                       ON DELETE CASCADE,
+
+                               CONSTRAINT fk_order_details_menu_item
+                                   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
+                                                                ('Margherita Pizza', 'Classic cheese pizza', 10.00, 'Pizza'),
+                                                                ('Cheeseburger', 'Beef burger with cheese', 8.50, 'Burger'),
+                                                                ('Spaghetti Bolognese', 'Pasta with meat sauce', 12.00, 'Pasta'),
+                                                                ('Coca Cola', 'Cold soft drink', 2.50, 'Drink');
 
 -- =======================================================
--- OPTIONAL TEST DATA
+-- OPTIONAL TEST USER
 -- =======================================================
---
--- You may insert sample users and orders for testing.
--- This section is optional.
---
--- INSERT INTO ...
-
 
+INSERT INTO users (username, password, email) VALUES
+    ('admin', 'hashed_password_here', 'admin@example.com');
 
 -- =======================================================
 -- 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;