Postgres Database Schema

Users

column name	data type	details
id	integer	not null, primary key
lastname	string	not null, indexed, unique
firstname	string	not null, indexed, unique
username	string	not null, indexed, unique
email	string	not null, indexed, unique
password_digest	string	not null
session_token	string	not null, indexed, unique
friends	array	not null
created_at	datetime	not null
updated_at	datetime	not null

• has_many posts
• has_many likes
• has_many friends
• has_one wall

Posts

column name	data type	details
id	integer	not null, primary key
title	string	not null
message	text	not null
poster_id	integer	not null, indexed, foreign key
created_at	datetime	not null
updated_at	datetime	not null

• belongs_to user
• has_many likes
• has_many comments

Comments

column name	data type	details
id	integer	not null, primary key
body	text	not null
author_id	integer	not null, foreign key
likes	array	not null
created_at	datetime	not null
updated_at	datetime	not null

• belongs_to user
• has_many likes

Likes

column name	data type	details
id	integer	not null, primary key
liker_id	integer	not null, indexed, foreign key
comment_id	integer	not null ,indexed, foreign key
created_at	datetime	not null
updated_at	datetime	not null

• belongs_to user

Friends

column name	data type	details
id	integer	not null, primary key
sender_id	integer	not null, indexed, foreign key
receiver_id	integer	not null, indexed, foreign key
pending	boolean	not null, presence
created_at	datetime	not null
updated_at	datetime	not null

• polymorphic assoication
• belongs_to user