database

database.sql

@@ -1,141 +1,123 @@
--- 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.
+
+
+DROP TABLE IF EXISTS order_details;
+DROP TABLE IF EXISTS orders;
+DROP TABLE IF EXISTS menu_items;
+DROP TABLE IF EXISTS users;
 
 
 
--- =======================================================
--- 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 NUMERIC(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 INTEGER NOT NULL,
+
+                        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+
+                        total_price NUMERIC(10,2) NOT NULL,
+
+
+                        CONSTRAINT fk_order_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 INTEGER NOT NULL,
+
+
+                               menu_item_id INTEGER NOT NULL,
+
+
+                               quantity INTEGER NOT NULL CHECK(quantity > 0),
+
+
+                               price NUMERIC(10,2) NOT NULL CHECK(price > 0),
+
+
+                               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 ...
 
 
 
--- =======================================================
--- OPTIONAL TEST DATA
--- =======================================================
---
--- You may insert sample users and orders for testing.
--- This section is optional.
---
--- INSERT INTO ...
+INSERT INTO menu_items
+(name, description, price, category)
+
+VALUES
+
+    ('Pizza','Cheese pizza',10.00,'Pizza'),
+
+    ('Burger','Beef burger',8.00,'Burger'),
+
+    ('Pasta','Italian pasta',12.00,'Pasta'),
+
+    ('Cola','Cold drink',2.50,'Drink');
 
 
 
--- =======================================================
--- VERIFICATION QUERIES
--- =======================================================
---
--- Uncomment these queries to verify your database.
---
--- SELECT * FROM ...;
--- SELECT * FROM ...;
--- SELECT * FROM ...;
--- SELECT * FROM ...;