== ER Diagram
[[Image(ticket:7:FINAL_DIAGRAMM.jpg, width=1400, height=1300)]]

== Data Requirements
=== Entities ===
**1. App User** - Entity for all users in the system\\ 
* user_id – primary key, numeric, required
* administrator_id - foreign key, required
* first_name – text type, required
* last_name - text type, required
* phone - text type, required
* email - text type, required
* password - text type, required

**2. Customer**\\
* (No extra attributes, inherits from User)

**3. Delivery Man**\\
* (No extra attributes, inherits from User)

**4. Restaurant Owner**\\
* (No extra attributes, inherits from User)

**5. Order**\\
* order_id – primary key, numeric, required
* user_id - foreign key, required
* address_id - foreign key, required
* restaurant_id - foreign key, required
* deliveryman_id - foreign key, required
* order_date – date, required
* order_status - text type, required
* comment - text type, required
* total_amount - numeric type


**6. Order Items**\\
* order_id - foreign key, required
* item_id - foreign key, required
* quantity - numeric type, required
* total_price- numeric type, required


**7. Item**\\
* item_id - primary key, numeric, required
* name- text type, required
* description - text type, required
* price - numeric type, required
* image_url - text type, optional


**8. Menu**\\
* menu_id- primary key, numeric, required
* restaurant_id - foreign key, required
* name- text type, required
* created_at - date, required
* updated_at- date, required


**9. Restaurant**\\
* restaurant_id - primary key, numeric, required
* address_id - foreign key, required
* name - text type, required
* email - text type, required
* phone_number - text type, required
* website_url - text type, required
* opening_time - time, required
* closing_time - time, required


**10. Restaurant Owners**\\
* restaurantowner_id - foreign key, required
* restaurant_id - foreign key, required


**11. Delivery Assignment**\\
* deliveryfirm_id - foreign key, required
* deliveryman_id - foreign key, required
* start_date - date, required
* end_date - date, required


**12. Delivery Firm**\\
* firm_id - primary key, numeric, required
* name - text type, required

**13. Earnings**\\
* earning_id - primary key, numeric, required
* restaurant_id - foreign key, required
* date - date, required
* source - text type, required
* amount - numeric type, required

**14. Costs**\\
* cost_id- primary key, numeric, required
* restaurant_id - foreign key, required
* date - date, required
* type - text type, required
* amount - numeric type, required

**15. Item Ingredient**\\
* item_id - foreign key, required
* ingredient_id - foreign key, required
* quantity - numeric type, required

**16. Ingredient**\\
* ingredient_id - primary key, numeric, required
* name - text type, required

**17. Address**\\
* address_id - primary key, numeric, required
* city - text type, required
* street - text type, required
* postal_code - text type, required

**18. User Addresses**\\
* address_id - foreign key, required
* user_id - foreign key, required

**19. Category**\\
* category_id - primary key, numeric, required
* name - text type, required
* description - text type, required

**20. Item Category**\\
* item_id - foreign key, required
* category_id - foreign key, required

**21. Restaurant Category**\\
* restaurant_id - foreign key, required
* category_id - foreign key, required

**22. Administrator**\\
* user_id - primary key, numeric, required
* authorized_from - date, required
* authorized_to - date, required

**23. Menu Item**\\
* menu_id - foreign key, required
* item_id - foreign key, required

**24. Shopping Cart**\\
* cart_id - primary key, numeric, required

**25. Cart Items**\\
* cart_id - foreign key, required
* item_id - foreign key, required
* quantity - numeric type, required


=== Relations===
=== 1:1 ===
* Restaurant → Menu  \\
    **''has''** – a relation which indicates that a restaurant has one menu and a menu belongs to only one restaurant.

* Address → Restaurant  \\
    **''is_located_at''** – a relation which indicates that a restaurant is located at one location, and a location can have only 1 restaurant.

* Admin → App User  \\
    **''manages''** – a relation which indicates that an admin is responsible for management of many users and a user is managed by a single admin.

* Customer → Shopping Cart  \\
    **''has''** – a relation which indicates that a customer has 1 shopping cart, and a shopping cart belongs to a user.

=== 1:M ===


* Customer → Order  \\
    **''places''** – a relation which indicates that a user can have place many orders, and an order can belong to one user.
\\

* Address → Order  \\
    **''is_delivered_to''** – a relation which indicates that an address can have multiple orders, and an order can be delivered to one address.
\\

* Restaurant → Costs  \\
    **''spends_on''** – a relation which indicates that a restaurant can have multiple costs, and a cost belongs to one restaurant.
\\
* Restaurant → Earnings\\
    **''receives''** – a relation which indicates that a restaurant can have multiple earnings, and an earning belongs to one restaurant.
\\
* Restaurant → Order\\
    **''resaturant_order''** – a relation which indicates that a restaurant can have multiple orders, and an order belongs to one restaurant.
\\
* Delivery Man → Order\\
    **''resaturant_order''** – a relation which indicates that a delivery man can have multiple orders, and an order belongs to one delivery man.
\\
=== M:N ===
* User ↔ User Addresses ↔ Address  \\
    **Junction: ** User Addresses solves M:N relation of User and Address, by storing the composite key (user_id, address_id)\\

    **''has''** – relation between User and Address where a user can have multiple addresses and an address can belong to multiple users.\\
\\
* Order ↔ Order Items ↔ Item  \\
    **Junction: ** Order Items solves M:N relation of Order and Item, by storing the composite key (order_id, item_id)\\

    **''has''** – relation between Order and Item where an order can have multiple items and an item can belong to multiple orders.\\
\\
* Delivery Man ↔ Delivery Assignment ↔ Delivery Firm \\
    **Junction: ** Delivery Assignment solves M:N relation of Delivery Man and Delivery Firm, by storing the composite key (deliveryman_id, deliveryfirm_id)\\

    **''assigned''** – relation between Delivery Man and Delivery Firm where a delivery man can be assigned to multiple firms and a firm can have multiple delivery men.\\

\\
* Restaurant Owner ↔ Restaurant Owners ↔ Restaurant \\
    **Junction: ** Restaurant Owners solves M:N relation of Restaurant Owner and Restaurant, by storing the composite key (user_id, restaurant_id)\\

    **''owns''** – relation between Restaurant Owner and Restaurant where a restaurant owner can own multiple restaurants and a restaurant can have multiple owners.\\

\\
* Item ↔ Item Ingredient ↔ Ingredient\\
    **Junction: ** Item Ingredient solves M:N relation of Item and Ingredient, by storing the composite key (item_id, ingredient_id)\\

    **''contains''** – relation between Item and Ingredient where an item can have multiple ingredients and an ingredient can belong to multiple items.\\
\\
* Item ↔ Item Category ↔ Category\\
    **Junction: ** Item Category solves M:N relation of Item and Category, by storing the composite key (category_id, item_id)\\

    **''has''** – relation between Item and Category, where a category can have multiple items and an item can belong to multiple categories.\\
\\
* Restaurant ↔ Restaurant Category ↔ Category\\
    **Junction: ** Restaurant Category solves M:N relation of Restaurant and Category, by storing the composite key (category_id, restaurant_id)\\

    **''has''** – relation between Category and Restaurant Category, where a category can have multiple restaurants, and a restaurant can belong to mutliple categories.\\
\\
* Menu ↔ Menu Item ↔ Item\\
    **Junction: ** Menu Item solves M:N relation of Menu and Item, by storing the composite key (menu_id, item_id)\\

    **''contains''** – relation between Menu and Item where an item can belong to many menu's and a menu can have many items.\\

\\
* Shopping Cart ↔ Shopping Cart Items ↔ Item\\
    **Junction: ** Shopping Cart Items solves M:N relation of Shopping Cart and Item, by storing the composite key (cart_id, item_id)\\

    **''cart_items''** – relation between Shopping Cart and Item where an item can belong to many shopping cart's and a shopping cart can have many items.\\