The Logical Data Model of the MENU Subject Area includes three groups of entities:

Menu Content entities

• Entity: MENU
• Entity: CATEGORY
• Entity: MENU_CATEGORY
• Entity: ITEM
• Entity: CATEGORY_ITEM
• Entity: DIET_TYPE
• Entity: DIET_ITEM

Menu Hours entities

• Entity: HOUR
• Entity: WEEK_DAY
• Entity: ITEM_HOUR
• Entity: MENU_HOUR

Menu Customizations entities

• Entity: CUSTOMIZATION
• Entity: CUSTOMIZATION_OPTION
• Entity: ITEM_CUSTOMIZATION
• Entity: ITEM_OPTION

This entity records information about all the Menus available at a Store. One Store can have many Menus available.

Attributes
ID	PRIMARY KEY
Store_ID	Lookup for the Store for which the Menu was recorded. NOT NULL
Name	Menu name. NOT NULL UNIQUE. Can't have two Menus with the same Name at a Store.
Description	Menu description.
Is_Active	Flag attribute to indicate if the Menu is still available at the Store or it was canceled permanently. NOT NULL
Comments	Internal notes used for clarifications on record content. Can be seen and edited only by Store Employees

List of food categories

Attributes
ID	PRIMARY KEY
Name	Name of food category. NOT NULL UNIQUE. Can't have two food categories with the same Name.
Description	Description of food category.
Is_Active	Flag attribute to indicate if the food category is still available or it was canceled permanently. NOT NULL
Comments	Internal notes used for clarifications on record content. Can be seen and edited only by Store Employees

This entity records all the food Categories assigned to a Menu. Each Menu can have many food Categories assigned.

Attributes
ID	PRIMARY KEY
Menu_ID	Lookup for the Menu to which the food Category is assigned. NOT NULL
Category_ID	Lookup for the food Category to be assigned to the Menu. NOT NULL
Description	Description.

CONSTRAINT UK_Menu_Category UNIQUE (Menu_ID, Category_ID). Cannot have the same food Category assigned twice to the same Menu.

List of all food items.

Attributes
ID	PRIMARY KEY
Name	Name of food item. NOT NULL UNIQUE. Can't have two food items with the same Name.
Description	Description of food item. This description can be displayed near the item Name when Customers select the item for an Order.
Calories	Number of calories of the food item.
Ingredients	Description of the ingredients of the food item.
Recipe	Description of the recipe of the food item.
In_Stock	Flag attribute to indicate if the food item is still available in stock. NOT NULL
Comments	Internal notes used for clarifications on record content. Can be seen and edited only by Store Employees

This entity records all the food Items assigned to a food Category. Each Category can have many food Items assigned.

Attributes
ID	PRIMARY KEY
Category_ID	Lookup for the food Category to which the food Item is assigned. NOT NULL
Item_ID	Lookup for the food Item to be assigned to the food Category. NOT NULL
Description	Description.

CONSTRAINT UK_Category_Item UNIQUE (Category_ID, Item_ID). Cannot have the same food Item assigned twice to the same food Category.

List of diet types.

Attributes
ID	PRIMARY KEY
Name	Diet type name. NOT NULL UNIQUE. Can't have two diet types with the same Name.
Description	Description of the diet type.
Is_Active	Flag attribute to indicate if the diet type is still available for customers or it was canceled permanently. NOT NULL

This entity records all the food Items that are assigned to a Diet Type. Each Diet Type can have many food Items assigned.

Attributes
ID	PRIMARY KEY
Diet_Type_ID	Lookup for the Diet Type to which the food Item is assigned. NOT NULL
Item_ID	Lookup for the food Item to be assigned to a Diet Type. NOT NULL
Description	Description.

CONSTRAINT UK_Diet_Item UNIQUE (Diet_Type_ID, Item_ID). Cannot have the same food Item assigned twice to the same Diet Type.

Day hours list. This entity facilitates Store and Menu hours selection and display.

Attributes
ID	PRIMARY KEY
Name	Hour name NOT NULL
AM_PM	Ante Meridian or Post Meridian hour. This attribute can have 'AM' or 'PM' value. NOT NULL
Description	Hour description

CONSTRAINT Hour_UK UNIQUE (Name, AM_PM)).

Week days list. This entity facilitates week days selection and display.

Attributes
ID	PRIMARY KEY
Name	Week day name NOT NULL UNIQUE
Description	Week day description

This entity records information if the Online Food Ordering Store can sell some food Items only on specific days of the week (for example only during weekends) and only for a limited time interval (for example from 2 PM to 4 PM).

Attributes
ID	PRIMARY KEY
Item_ID	Item lookup. The food item for which the Item hours are recorded. NOT NULL
Week_Day_ID	Week day lookup. The day of the week when the food item can be ordered. NOT NULL
Start_Hour_ID	Start hour lookup. The start hour from which the food item can be ordered. NOT NULL
End_Hour_ID	End hour lookup. The end hour after which the item can not be ordered. NOT NULL
Comments	Internal notes used for clarifications on record content. Can be seen and edited only by Store Employees.

This entity records information about the Menus available only on specific days of the week (for example only during weekends) and only for a limited time interval (for example from 2 PM to 4 PM).

Attributes
ID	PRIMARY KEY
Menu_ID	Menu lookup. The Menu for which the Menu hours are recorded. NOT NULL
Week_Day_ID	Week day lookup. The week day when the Menu is available for a limited time interval. NOT NULL
Start_Hour_ID	Menu start hour lookup. NOT NULL
End_Hour_ID	Menu end hour lookup. NOT NULL
Comments	Internal notes used for clarifications on record content. Can be seen and edited only by Store Employees.

List of customizations that can be applied to a food item: 'Topping', 'Portion size' etc. The Customer has the possibility to choose from the pre-defined customizations.

Attributes
ID	PRIMARY KEY
Name	Customization name. Can't have two Customizations with the same Name. NOT NULL UNIQUE
Display_Title	Display title for Customer. Can't have two Customizations with the same Display title. NOT NULL UNIQUE
Description	Customization description.
Is_Active	Flag attribute to indicate if the Customization is still available or the Customization was canceled permanently and the Customers can not select it anymore. NOT NULL

This entity records all the Customization Options assigned to a Customization.

Attributes
ID	PRIMARY KEY
Customization_ID	Lookup for the Customization to which the Customization Option is assigned. NOT NULL
Name	Name of the customization option. NOT NULL UNIQUE. Can't have two customization options with the same Name.
Description	Description of customization option.
Is_Active	Flag attribute to indicate if the customization option is still available for customizations or it was canceled permanently. NOT NULL

This entity records all the Customizations available for a food Item. Each food Item can have 0, 1 or many Customizations available.

Attributes
ID	PRIMARY KEY
Item_ID	Lookup for the food Item to which the Customization is assigned. NOT NULL
Customization_ID	Lookup for the Customization to be assigned to the food Item. NOT NULL
Comments	Internal notes used for clarifications on record content. Can be seen and edited only by Store Employees.

CONSTRAINT UK_Item_Customization UNIQUE (Item_ID, Customization_ID). Cannot have the same Customization assigned twice to the same food Item.

This entity records all the Customization Options available for an Item.

For example the food Item: 'Apple Cake' has the assigned Customization: 'Topping'. See Entity: ITEM_CUSTOMIZATION for more information.

If for the food Item: 'Apple Cake' you would want to restrict the Customization: 'Topping' only to the Customization Option: 'Vanilla', then you should enter a record in the ITEM_OPTION table as in the example below.

In this case all the other 'Topping' customization options ('Chocolate', 'Strawberry' etc.) are not available for selection when a Customer will add the 'Apple Cake' item to an Order.

Attributes
ID	PRIMARY KEY
Item_Customization_ID	Lookup for the record in the ITEM_CUSTOMIZATION table to which the Customization Option is assigned. NOT NULL
Customization_Option_ID	Lookup for the Customization option to be assigned. NOT NULL
In_Stock	Flag attribute to indicate if the Item Option is still available in stock. For example the In_Stock attribute can indicate if the Customization: 'Topping' with the Customization Option: 'Chocolate' is in stock for the Item: 'Ice-cream'. The In_Stock flag can control the decision to suspend a Customization Option for an Item and continue the Customization Option for other Items. NOT NULL
Default_Quantity	This is an indication for Customer about the default quantity of the customization that is delivered with the Item. For example for the Customization: 'Topping', for the Customization Option: 'Chocolate' for the Item: 'Ice cream' you can set the Default_Quantity: 1. That means if Customer would want to add 'Chocolate' topping two times to the Item, then should pay separately for the quantity over the default quantity. See Subject Area: PRICE AND DISCOUNT for more information. NOT NULL
Comments	Internal notes used for clarifications on record content. Can be seen and edited only by Store Employees.

UK_Item_Option UNIQUE (Item_Customization_ID, Customization_Option_ID). Cannot have the same Customization Option assigned twice to the same Item_Customization record.