Struttura database di facebook:

Facebook like data structure:

User
------------
UserId (PK)

Item
-------------
ItemId (PK)
ItemType (discriminator column)
OwnerId (FK to User)

Status
------------
ItemId (PK, FK to Item)
StatusText 

RelationshipUpdate
------------------
ItemId (PK, FK to Item)
RelationshipStatus
RelationTo (FK to User)

Like
------------
OwnerId (FK to User)
ItemId (FK to Item)
Compound PK of OwnerId, ItemId

Struttura Wall:
Script già fatti:
http://www.thewallscript.com/
http://w3lessons.info/2013/04/21/facebook-wall-script-3-0-timeline-oauth-location-sharing-smileys-many-more/

imitazione facebook:

http://w3lessons.info/2013/09/24/facebook-wall-script-4-0-with-php-codeigniter-mvc-framework/