Question

我是尝试理解ActiveRecord中的关联的新手，它当前正在将#<ActiveRecord::Relation []>返回到我在Web控制台中运行的查询。

简而言之，我阅读了Rails指南并认为has_and_belongs_to_many是最佳解决方案。我的终端显示它正在运行查询，但它似乎只是返回一个空数组，输出在下面。

Processing by ScheduleController#show as HTML Parameters: {"id"=>"1"} Schedule Load (0.2ms) SELECT "schedules".* FROM "schedules" WHERE "schedules"."id" = ? LIMIT ? [["id", 1], ["LIMIT", 1]] Player Load (0.3ms) SELECT "players".* FROM "players" WHERE "players"."team" = ? [["team", "@schedule.home"]]

我有一个Schedule和一个Players模型，其目的是根据主队和客队名称返回一个球员名单。

模型/ player.rb

class Player < ApplicationRecord
 has_and_belongs_to_many :schedules
end

模型/ schedule.rb

class Schedule < ApplicationRecord
  has_and_belongs_to_many :players
end

分贝/迁移/（数字）_create_schedules.rb

class CreateSchedules < ActiveRecord::Migration[5.0]
  def change
    create_table :schedules do |t|
      t.string :leagueGame
      t.string :home
      t.string :homeAbr
      t.string :away
      t.string :awayAbr
      t.string :venue
      t.string :prettyDate
      t.string :homeLogo
      t.string :homeLogoLarge
      t.string :awayLogo
      t.string :awayLogoLarge
      t.date :date

      t.timestamps
    end

    create_table :player_schedule do |t|
      t.belongs_to :player, index: true
      t.belongs_to :schedule, index: true
    end
  end
end

分贝/迁移/（数字）_create_players.rb

class CreatePlayers < ActiveRecord::Migration[5.0]
  def change
    create_table :players do |t|
      t.string :name
      t.string :team
      t.string :shoots
      t.string :catches
      t.string :position
      t.string :abr
      t.integer :number
      t.integer :gp
      t.integer :goals
      t.integer :assists
      t.integer :points
      t.integer :pim
      t.integer :plusMinus
      t.decimal :gaa
      t.integer :svs

      t.timestamps
    end   
  end
end

控制器/ schedule_controller.rb

# For brevity
  def show
    @schedule = Schedule.find(params[:id])
    @home_lineup = Player.where(team: '@schedule.home')
  end

@home_lineup是返回空数组的调用。我可以调用@schedule.home并显示正确的团队名称，但是我可以像在表查找中一样调用它吗？

Answer 1

替换

@home_lineup = Player.where(team: '@schedule.home')

与

@home_lineup = Player.where(team: @schedule.home)

根据您的代码，您正在搜索名称为＆＃39; @ schedule.home＆＃39;而不是实际的团队名称。

Rails 5返回`＃<activerecord :: relation [] =“”>`

1 个答案: