DB設計

users table

column	Type	Option
name	string	null: false, unique: true
email	varchar	null: false, unique: true
password	varchar	null: false,

Association

• has_many : groups,through: group_users
• has_many : messages
• has_many : group_users

groups tables

column	Type	Option
name	string	null: false, unique: true

Association

• has_many : users,through: group_users
• has_many : messages
• has_many : group_users

group_users table

column	Type	Option
group_id	integer	null: false, foreign_key: true
user_id	integer	null: false, foreign_key: true

Association

• belongs_to : user
• belongs_to : group

messages table

column	Type	Option
body	text
image	string
group_id	integer	null: false, foreign_key: true
user_id	integer	null: false, foreign_key: true

Association

• belongs_to : user
• belongs_to : group