テーブル設計

users

Column	Type	Options
email	string	null: false, unique: true
nickname	string	null: false
encrypted_password	string	null: false
first_name	string	null: false
last_name	string	null: false
kana_first_name	string	null: false
kana_last_name	string	null: false
birthdate	date	null: false

• has_many :purchases
• has_many :items

items

Column	Type	Options
item_name	string	null: false
description	text	null: false
detail_category_id	integer	null: false
detail_condition_id	integer	null: false
delivery_format_id	integer	null: false
region_id	integer	null: false
arrival_id	integer	null: false
price	integer	null: false
user	references	foreign_key: true

• belongs_to :user
• has_one :purchase

addresses

Column	Type	Options
postal_code	string	null: false
region_id	integer	null: false
city	string	null: false
address_no	string	null: false
building_no	string
phone_number	string	null: false
purchase	references	foreign_key: true

• belongs_to :purchase

purchases

Column	Type	Options
user	references	foreign_key: true
item	references	foreign_key: true

• belongs_to :user
• has_one :address
• belongs_to :item

（ここに追記していく）