update multiple classes

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2026-06-27 21:12:42 +03:30
parent 3573dc1f58
commit dd6e81bcd5
13 changed files with 224 additions and 144 deletions
+37 -132
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-- 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.
CREATE TABLE users (
id SERIAL PRIMARY KEY,
username VARCHAR(20) NOT NULL UNIQUE,
password VARCHAR(20) NOT NULL,
email VARCHAR(100) UNIQUE
);
CREATE TABLE menu_items(
id SERIAL PRIMARY KEY,
name VARCHAR(50) NOT NULL ,
description TEXT,
price NUMERIC(10, 2) NOT NULL CHECK ( price>0 ),
category VARCHAR(50)
);
-- =======================================================
-- 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 orders(
id SERIAL PRIMARY KEY,
user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
created_at TIMESTAMP NOT NULL,
total_price NUMERIC(10, 2) NOT NULL CHECK (total_price >= 0)
);
-- =======================================================
-- 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 order_detail(
id SERIAL PRIMARY KEY,
order_id INTEGER NOT NULL REFERENCES orders(id) ON DELETE CASCADE,
menu_item_id INTEGER NOT NULL REFERENCES menu_items(id),
quantity INTEGER NOT NULL CHECK (quantity > 0),
price NUMERIC(10, 2) NOT NULL CHECK (price > 0)
);
INSERT INTO menu_items (name, description, price, category)
VALUES
('Margherita Classica', 'Tomato sauce, fresh mozzarella, and basil on a crispy thin crust', 16.00, 'Pizza'),
('Smoked BBQ Bacon Burger', 'Angus beef with cheddar, bacon, onion rings, and BBQ sauce on a brioche bun.', 14.50, 'Burger'),
('Truffle Mushroom Fettuccine', 'Creamy fettuccine with mushrooms, Parmesan, and a touch of truffle oil.', 18.00, 'Pasta'),
('Cola', 'Cold soft drink', 2.50, 'Drink');
-- =======================================================
-- 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 ...
-- =======================================================
-- 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 ...
-- =======================================================
-- INITIAL MENU DATA
-- =======================================================
--
-- Insert at least 3 food or drink items.
--
-- Example categories:
-- - Pizza
-- - Burger
-- - Pasta
-- - Drink
--
-- INSERT INTO ...
-- =======================================================
-- OPTIONAL TEST DATA
-- =======================================================
--
-- You may insert sample users and orders for testing.
-- This section is optional.
--
-- INSERT INTO ...
-- =======================================================
-- 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_detail;