Table of Contents

1. Database Schema
2. Joins Tables
3. Associations

Database Schema

Users

Column	Data Type	Details
id	integer	not null, primary key
username	string	not null, unique, indexed
email	string	not null, unique, indexed
password_digest	string	not null
session_token	string	not null, unique, indexed
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

Photos

Column	Data Type	Details
id	integer	not null, primary key
title	string
description	text
uploader_id	integer	not null, foreign key, indexed
created_at	datetime	not null
updated_at	datetime	not null

• index on user_id
• uploader will reference Users:id

Albums

Column	Data Type	Details
id	integer	not null, primary key
title	string	not null
description	text
user_id	integer	not null, foreign key, indexed
created_at	datetime	not null
updated_at	datetime	not null

• index on user_id
• user_id will reference Users:id

Comments

Column	Data Type	Details
id	integer	not null, primary key
body	text	not null
author_id	integer	not null, foreign key, indexed
photo_id	integer	not null, foreign key, indexed
created_at	datetime	not null
updated_at	datetime	not null

• index on user_id
• index on photo_id
• author_id will reference Users:id
• photo_id will reference Photos:id

Tags

Column	Data Type	Details
id	integer	not null, primary key
name	string	not null, unique
created_at	datetime	not null
updated_at	datetime	not null

• index on name

---

Joins Tables

Album Photos

Column	Data Type	Details
id	integer	not null, primary key
album_id	integer	not null, foreign key
photo_id	integer	not null, foreign key

• albums can have many photos
• photos can belong to many albums
• album_id will reference Albums:id
• photo_id will reference Photos:id

Photo Tags

Column	Data Type	Details
id	integer	not null, primary key
photo_id	integer	not null, foreign key
tag_id	integer	not null, foreign key

• photos can have many tags
• tags belong to many photos
• photo_id will reference Photos:id
• tag_id will reference Tags:id

---

Associations

User

Association	Primary Key	Foreign Key	Class Name
has_many: :photos	:id	:user_id	Photo
has_many: :comments	:id	:user_id	Comment
has_many: :albums	:id	:user_id	Album

Photo

Association	Primary Key	Foreign Key	Class Name
belongs_to_many: :albums	:id	:album_id	Album
belongs_to: :user	:id	:user_id	User
has_many: :comments	:id	:photo_id	Comment
has_many: :tags	:id	:photo_id	Tag

Album

Association	Primary Key	Foreign Key	Class Name
belongs_to: :user	:id	:user_id	User
has_many: :photos	:id	:album_id	Photo

Comment

Association	Primary Key	Foreign Key	Class Name
belongs_to: :user	:id	:user_id	User
belongs_to: :photos	:id	:photo_id	Photo

Tag

Association	Primary Key	Foreign Key	Class Name
belongs_to_many: :photos	:id	:photo_id	Photo