Schema

Database Schema

users

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

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

comments

column name	data type	details
id	integer	not null, primary key
body	string	not null
author_id	integer	not null, indexed, foreign key
image_id	integer	not null, indexed, foreign key
created_at	datetime	not null
updated_at	datetime	not null

• author_id references users
• image_id references images
• index on author_id
• index on image_id

likes

column name	data type	details
id	integer	not null, primary key
user_id	integer	not null, indexed, foreign key
likeable_id	integer	not null, indexed, foreign key
likeable_type	integer	not null, indexed
created_at	datetime	not null
updated_at	datetime	not null

• user_id references users
• likeable_id and likeable_type references polymorphic association
• index on :user_id, unique: true
• index on [likeable_id, likeable_type, user_id], unique: true

follows

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

• user_id references users
• followed_user_id references followed_users
• index on [:user_id, :followed_user_id] unique: true
• index on :user_id, unique: true

posts

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

• author_id references author
• index on :author_id