complete

database.sql

@@ -1,141 +1,93 @@
--- 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 CASCADE;
+DROP TABLE IF EXISTS orders CASCADE;
+DROP TABLE IF EXISTS menu_items CASCADE;
+DROP TABLE IF EXISTS users CASCADE;
 
 -- =======================================================
 -- 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 BIGSERIAL PRIMARY KEY,
+    username VARCHAR(50) NOT NULL UNIQUE,
+    password_hash VARCHAR(255) NOT NULL,
+    email VARCHAR(100) UNIQUE
+);
 
 -- =======================================================
 -- 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 BIGSERIAL 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 BIGSERIAL PRIMARY KEY,
+    user_id BIGINT NOT NULL,
+    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    total_price NUMERIC(10,2) NOT NULL CHECK (total_price >= 0),
 
+    CONSTRAINT fk_orders_user
+        FOREIGN KEY (user_id)
+        REFERENCES users(id)
+        ON DELETE CASCADE
+);
 
 -- =======================================================
--- ORDER DETAIL TABLE
+-- ORDER DETAILS 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 BIGSERIAL PRIMARY KEY,
+    order_id BIGINT NOT NULL,
+    menu_item_id BIGINT NOT NULL,
+    quantity INTEGER NOT NULL CHECK (quantity > 0),
+    item_price NUMERIC(10,2) NOT NULL CHECK (item_price > 0),
 
+    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
+('Pepperoni Pizza', 'Classic pepperoni pizza', 10.99, 'Pizza'),
+('Cheese Burger', 'Beef burger with cheese', 8.50, 'Burger'),
+('Chicken Pasta', 'Creamy chicken pasta', 12.75, 'Pasta'),
+('Coca Cola', 'Soft drink', 2.50, 'Drink');
 
 -- =======================================================
 -- OPTIONAL TEST DATA
 -- =======================================================
---
--- You may insert sample users and orders for testing.
--- This section is optional.
---
--- INSERT INTO ...
 
+INSERT INTO users (username, password_hash, email)
+VALUES
+('ali', 'hashed_password_1', 'ali@example.com'),
+('sara', 'hashed_password_2', 'sara@example.com');
 
+INSERT INTO orders (user_id, total_price)
+VALUES
+(1, 24.48);
 
--- =======================================================
--- VERIFICATION QUERIES
--- =======================================================
---
--- Uncomment these queries to verify your database.
---
--- SELECT * FROM ...;
--- SELECT * FROM ...;
--- SELECT * FROM ...;
--- SELECT * FROM ...;
+INSERT INTO order_details (order_id, menu_item_id, quantity, item_price)
+VALUES
+(1, 1, 2, 10.99),
+(1, 4, 1, 2.50);