complete

2026-06-22 19:42:41 +03:30
parent 00f990c653
commit e10d7f02e5
21 changed files with 569 additions and 234 deletions
@@ -1,141 +1,39 @@
-- 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(50) NOT NULL UNIQUE,
+                       password VARCHAR(255) NOT NULL,
+                       email VARCHAR(100)
+);

+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)
+);

+CREATE TABLE customer_orders (
+                                 id SERIAL PRIMARY KEY,
+                                 user_id INTEGER NOT NULL,
+                                 created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+                                 total_price DECIMAL(10,2) NOT NULL,
+                                 FOREIGN KEY (user_id) REFERENCES users(id)
+);

-- =======================================================
-- 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 order_details (
+                               id SERIAL PRIMARY KEY,
+                               order_id INTEGER NOT NULL,
+                               menu_item_id INTEGER NOT NULL,
+                               quantity INTEGER NOT NULL CHECK (quantity > 0),
+                               price DECIMAL(10,2) NOT NULL,
+                               FOREIGN KEY (order_id) REFERENCES customer_orders(id),
+                               FOREIGN KEY (menu_item_id) REFERENCES menu_items(id)
+);

-
-
-- =======================================================
-- 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 ...
-
-
-
-- =======================================================
-- 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 ...;
+INSERT INTO menu_items (name, description, price, category) VALUES
+                                                                ('Margherita Pizza', 'Classic tomato and mozzarella', 10.00, 'Pizza'),
+                                                                ('Cheeseburger', 'Beef patty with cheddar cheese', 8.00, 'Burger'),
+                                                                ('Spaghetti Carbonara', 'Pasta with egg, cheese, pancetta', 12.00, 'Pasta'),
+                                                                ('Caesar Salad', 'Romaine lettuce with Caesar dressing', 7.00, 'Salad'),
+                                                                ('Cola', 'Refreshing carbonated drink', 2.50, 'Drink');