Ruby on rails Rails 4.2中的关系：1对多或2对1

我将如何描述它的工作原理：

用户

Alice可以启动与另一个

用户的
交换
。因此，Alice是这个
交换的发起用户，Bob是被请求的用户

一个
用户
可以有许多
交换
s

一个
交换
有一个
发起用户
和一个
请求用户
。
我不确定这是一对一关系还是一对多关系，因为两者都属于
用户
，但地址不同

一个
交易所
正好有两个
评级
s，但与以前相同的问题也适用。我不知道这是一对一还是一对多的关系。
发起用户
和
请求用户
中的每一个都可以进行
评分
。
然后分别是
启动用户评级
或
请求的用户评级

一个
评级
只属于一个
交易所

我的问题：

我几乎可以肯定，有一种比我现在使用的方法简单得多的方法，可能只是使用
ActiveRecord
关系。
它现在起作用了，但我对它不满意

所以我想我的问题是：


那些
启动用户
/
请求的用户
和
启动用户评级
/
请求的用户评级
关系是否都是1对多
还是两个1比1
有没有更好的方法来建立这个星座的关系
如果不是的话，我如何让结构变得不那么粗糙而更像rails-y

不是真正的UML:


代码：

在
app/models/user.rb中

# Exchanges
has_many :initiated_exchanges, class_name: "Exchange",
                               foreign_key: "init_user_id"
has_many :requested_exchanges, class_name: "Exchange",
                               foreign_key: "req_user_id"
# Ratings
has_many :init_user_ratings, through: :initiated_exchanges
has_many :req_user_ratings, through: :requested_exchanges

# Users
belongs_to :init_user, class_name: "User",
                       foreign_key: "init_user_id"
belongs_to :req_user, class_name: "User",
                      foreign_key: "req_user_id"
# Ratings
belongs_to :init_user_rating, class_name: "Rating",
                              foreign_key: "init_user_rating_id"
belongs_to :req_user_rating, class_name: "Rating",
                             foreign_key: "req_user_rating_id"

def exchange
  Exchange.find_by("init_user_rating_id=? or req_user_rating_id=?", id, id)
end

create_table "exchanges", force: :cascade do |t|
  t.integer  "init_user_id",        null: false
  t.integer  "req_user_id",         null: false
  t.integer  "init_user_rating_id"
  t.integer  "req_user_rating_id"

  t.datetime "created_at",          null: false
  t.datetime "updated_at",          null: false
end

create_table "ratings", force: :cascade do |t|
  t.integer  "rating"
  t.text     "text",                limit: 1000

  t.datetime "created_at",          null: false
  t.datetime "updated_at",          null: false
end

在
app/models/exchange.rb

# Exchanges
has_many :initiated_exchanges, class_name: "Exchange",
                               foreign_key: "init_user_id"
has_many :requested_exchanges, class_name: "Exchange",
                               foreign_key: "req_user_id"
# Ratings
has_many :init_user_ratings, through: :initiated_exchanges
has_many :req_user_ratings, through: :requested_exchanges

# Users
belongs_to :init_user, class_name: "User",
                       foreign_key: "init_user_id"
belongs_to :req_user, class_name: "User",
                      foreign_key: "req_user_id"
# Ratings
belongs_to :init_user_rating, class_name: "Rating",
                              foreign_key: "init_user_rating_id"
belongs_to :req_user_rating, class_name: "Rating",
                             foreign_key: "req_user_rating_id"

def exchange
  Exchange.find_by("init_user_rating_id=? or req_user_rating_id=?", id, id)
end

create_table "exchanges", force: :cascade do |t|
  t.integer  "init_user_id",        null: false
  t.integer  "req_user_id",         null: false
  t.integer  "init_user_rating_id"
  t.integer  "req_user_rating_id"

  t.datetime "created_at",          null: false
  t.datetime "updated_at",          null: false
end

create_table "ratings", force: :cascade do |t|
  t.integer  "rating"
  t.text     "text",                limit: 1000

  t.datetime "created_at",          null: false
  t.datetime "updated_at",          null: false
end

在
app/models/rating.rb中

# Exchanges
has_many :initiated_exchanges, class_name: "Exchange",
                               foreign_key: "init_user_id"
has_many :requested_exchanges, class_name: "Exchange",
                               foreign_key: "req_user_id"
# Ratings
has_many :init_user_ratings, through: :initiated_exchanges
has_many :req_user_ratings, through: :requested_exchanges

# Users
belongs_to :init_user, class_name: "User",
                       foreign_key: "init_user_id"
belongs_to :req_user, class_name: "User",
                      foreign_key: "req_user_id"
# Ratings
belongs_to :init_user_rating, class_name: "Rating",
                              foreign_key: "init_user_rating_id"
belongs_to :req_user_rating, class_name: "Rating",
                             foreign_key: "req_user_rating_id"

def exchange
  Exchange.find_by("init_user_rating_id=? or req_user_rating_id=?", id, id)
end

create_table "exchanges", force: :cascade do |t|
  t.integer  "init_user_id",        null: false
  t.integer  "req_user_id",         null: false
  t.integer  "init_user_rating_id"
  t.integer  "req_user_rating_id"

  t.datetime "created_at",          null: false
  t.datetime "updated_at",          null: false
end

create_table "ratings", force: :cascade do |t|
  t.integer  "rating"
  t.text     "text",                limit: 1000

  t.datetime "created_at",          null: false
  t.datetime "updated_at",          null: false
end

从
app/db/schema.rb

# Exchanges
has_many :initiated_exchanges, class_name: "Exchange",
                               foreign_key: "init_user_id"
has_many :requested_exchanges, class_name: "Exchange",
                               foreign_key: "req_user_id"
# Ratings
has_many :init_user_ratings, through: :initiated_exchanges
has_many :req_user_ratings, through: :requested_exchanges

# Users
belongs_to :init_user, class_name: "User",
                       foreign_key: "init_user_id"
belongs_to :req_user, class_name: "User",
                      foreign_key: "req_user_id"
# Ratings
belongs_to :init_user_rating, class_name: "Rating",
                              foreign_key: "init_user_rating_id"
belongs_to :req_user_rating, class_name: "Rating",
                             foreign_key: "req_user_rating_id"

def exchange
  Exchange.find_by("init_user_rating_id=? or req_user_rating_id=?", id, id)
end

create_table "exchanges", force: :cascade do |t|
  t.integer  "init_user_id",        null: false
  t.integer  "req_user_id",         null: false
  t.integer  "init_user_rating_id"
  t.integer  "req_user_rating_id"

  t.datetime "created_at",          null: false
  t.datetime "updated_at",          null: false
end

create_table "ratings", force: :cascade do |t|
  t.integer  "rating"
  t.text     "text",                limit: 1000

  t.datetime "created_at",          null: false
  t.datetime "updated_at",          null: false
end