Question

如何从较少的查询中加载此内容？

当前代码; 控制器;

@players = @season.players.includes(:stats)

视图;

<% @players.each do |player| %>
    <%= player.stats.where(season: @season).each do |stat| %>
    <% end %>
<% end %>

查询;

 Season Load (0.1ms)  SELECT  "seasons".* FROM "seasons" WHERE "seasons"."id" = ? LIMIT 1  [["id", 1]]
  Player Load (0.2ms)  SELECT "players".* FROM "players" INNER JOIN "player_seasons" ON "players"."id" = "player_seasons"."player_id" WHERE "player_seasons"."season_id" = ?  [["season_id", 1]]
  Stat Load (0.3ms)  SELECT "stats".* FROM "stats" WHERE "stats"."player_id" IN (1, 2)
  Stat Load (0.1ms)  SELECT "stats".* FROM "stats" WHERE "stats"."player_id" = ? AND "stats"."season_id" = 1  [["player_id", 1]]
  Stat Load (0.1ms)  SELECT "stats".* FROM "stats" WHERE "stats"."player_id" = ? AND "stats"."season_id" = 1  [["player_id", 2]]
  Rendered seasons/show.html.erb within layouts/application (5.4ms)

谢谢。

Answer 1

您是否尝试过preload或eager_load而不是includes？

有很多关于各种联接的好信息可以在这里找到：http://blog.bigbinary.com/2013/07/01/preload-vs-eager-load-vs-joins-vs-includes.html

包括协会

1 个答案: