Database Schema

users

column name	data types	detail
id	integer	not null, primary key
username	string	not null, indexed, unique
password_digest	string	not null
session_token	string	not null, indexed, unique
image_url	string

• index on username, unique: true
• index on email, unique: true
• index on session_token, unique: true

pictures

column name	data types	detail
id	integer	not null, primary key
title	string	not null, indexed, unique
image_url	string
category_id	integer	not null, indexed, foreign key

• index on title, unique: true
• index on category_id
• category_id references categories

categories

column name	data types	detail
id	integer	not null, primary key
title	string	not null, indexed, unique

• index on title, unique: true

follows

column name	data types	detail
id	integer	not null, primary key
category_id	integer	not null, indexed, foreign key
user_id	integer	not null, indexed, foreign key

• category_id references categories
• user_id references users
• index on [:category_id, :user_id], unique: true