Database Schema

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

groups

column name	data type	details
id	integer	not null, primary key
name	string	not null
description	string
owner_id	integer	not null, indexed, foreign key
created_at	datetime	not null
updated_at	datetime	not null

• owner_id references users
• index on owner_id

expenses

column name	data type	details
id	integer	not null, primary key
name	string	not null
amount	integer	not null
owner_id	integer	not null, indexed, foreign key
date	date	not null
created_at	datetime	not null
updated_at	datetime	not null

• owner_id references users
• index on owner_id

transactions

column name	data type	details
id	integer	not null, primary key
amount	integer	not null
payer_id	integer	not null, indexed, foreign key
expense_id	integer	not null, indexed, foreign key
created_at	datetime	not null
updated_at	datetime	not null

• payer_id references users
• expense_id references expenses
• index on payer_id
• index on expense_id

payments

column name	data type	details
id	integer	not null, primary key
amount	integer	not null
payee_id	integer	not null, indexed, foreign key
payer_id	integer	not null, indexed, foreign key
date	date	not null
created_at	datetime	not null
updated_at	datetime	not null

• payee_id references users
• payer_id references users
• index on payee_id
• index on payer_id

comments

column name	data type	details
id	integer	not null, primary key
title	string
body	text	not null
author_id	integer	not null, indexed, foreign key
commentable_type	string	not null, polymorphic table
commentable_id	integer	not null, indexed, polymorphic foreign key
created_at	datetime	not null
updated_at	datetime	not null

• author_id references users
• commentable_type references expenses or transactions
• index on author_id
• index on commentable_id

Joins Tables

friendships

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

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

members

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

• user_id references users
• group_id references groups
• index on user_id
• index on group_id