使用 ID 将 JSON 发布到 rails 会导致错误

Question

我有一个game 和两个teams。我希望能够 POST 这样的事情 /games --

{"game":{"home_team":1,"away_team":2,"time":"Wed, 12 Aug 2015 08:08:08 -0500","winner":1,"home_score":2,"away_score":1}}

我的 game.rb 模型看起来像这样 --

class Game < ActiveRecord::Base
  belongs_to :home_team_id, :class_name => "Team"
  belongs_to :away_team_id, :class_name => "Team"
  belongs_to :winner_id, :class_name => "Team"
...
end

我的team.rb 模型看起来像这样--

class Team < ActiveRecord::Base
  has_many :home_games, class_name: "Game"
  has_many :away_games, class_name: "Game"
  has_many :winners, class_name: "Game"
...
end

game 的架构如下 --

  create_table "games", force: :cascade do |t|
    t.integer  "home_team_id"
    t.integer  "away_team_id"
    t.datetime "time"
    t.integer  "home_score"
    t.integer  "away_score"
    t.integer  "winner_id"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
  end

  add_index "games", ["away_team_id"], name: "index_games_on_away_team", using: :btree
  add_index "games", ["home_team_id"], name: "index_games_on_home_team", using: :btree
  add_index "games", ["winner_id"], name: "index_games_on_winner", using: :btree

我得到的错误是Team(#70124766940300) expected, got Fixnum(#70124749378140)"

Answer 1

这里缺少一个基本设置。

架构不应为"home_team" 和"away_team"，而应为"home_team_id" 和"away_team_id"

同样在模型中，不需要定义foreign_key: "home_team" 或foreign_key: "away_team"。 Rails 约定（我相信）会假设belongs_to :home_team, :class_name => "Team" 的外键为"home_team_id"

如果您在数据库级别（架构）考虑它，数据库不会在游戏表中存储有关home_team 的所有信息。它只有一个home_game_id，所以它引用了home_game。这样，数据库就不需要为每个关联复制一堆数据。

一旦这个问题被修复，Controller 中可能会出现其他错误，但该错误消息告诉您的是它获取的是 Team 类而不是 Fixnum，因此它可能在某处调用 game.home_team 并对其进行处理，但您只是从数据库中提取 home_team ID，而不是关联。