Storing multiple Foreign Keys in MySQL

Question

I am in a design dilemma, I am designing a database for a house rental application, the point that got me stuck is the amenities of the house, given that a house can have multi amenities like Ceiling board,Dishwasher, Refrigerator, Paved yard, Wall fence etc How do I store such a house in the database? Some suggestion I have been given are(Simplified tables):

`  |id |description|amenities|
   |1  |           |         | 

1. Store amenity ids eg 1,2,3,4 in the amenities column

2. Store the amenity strings in the amenities column

Between the two option 1 is best because am saving memory but isn't there a better way to store multiple ids than this?

Answer 1

You can use EAV model for that, you will save memory, but will lose performance on select, or use sparse columns

EAV approach:

EAV table:

• entityId
• attributeId
• value

Attribute table:

• attributeId
• attribute name

Entity table:

• entityId
• entity name

Attributes would be

Ceiling board,Dishwasher, Refrigerator, Paved yard, Wall fence etc

Entities

house 1, house 2

Sparse columns:

House table:

• House id
• Your attribute(Nullable)
• Your attribute2(Nullable)
• Your attribute3(Nullable)

Simple mapping:

House table:

• houseId
• house name

Amenities table:

• amenityId
• name

HouseAmenitiesMapping:

• houseId
• amenityId