Database Schema

users

column name	data type	details
id	integer	not null, primary key
username	string	not null, indexed, unique
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

posts

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

• user_id references users id
• index on user_id

likes

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

• user_id references users id
• post_id references posts id
• index on [post_id, user_id], unique: true
• index on user_id, unique: true

comments

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

• user_id references users id
• post_id references posts id

Follows

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

• user_id references users id
• follower_id references users id
• index on [follower_id, user_id], unique: true
• index on user_id, unique: true