add database.sql

database.sql

@@ -1,141 +1,53 @@
--- 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 ...
+CREAT TABLE users(
+      id SERIAL PRIMARY KEY,
+      username VARCHAR(50) NOT NULL UNIQUE,
+      password VARCHAR(100) 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)
+);
+
+
+CREATE TABLE orders (
+     id SERIAL PRIMARY KEY,
+     user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+     created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+     total_price NUMERIC(10, 2) NOT NULL CHECK (total_price >= 0)
+);
 
 
 
--- =======================================================
--- 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 order_details (
+     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
+    ('Pizza', 'Cheese pizza with tomato sauce', 12.50, 'Pizza'),
+    ('Burger', 'Beef burger with fries', 9.00, 'Burger'),
+    ('Pasta', 'Pasta with Alfredo sauce', 11.00, 'Pasta'),
+    ('Cola', 'Cold soft drink', 2.50, 'Drink');
+
+SELECT * FROM users;
+SELECT * FROM menu_items;
+SELECT * FROM orders;
+SELECT * FROM order_details;
 
 
 
--- =======================================================
--- 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 ...;