create_table "attendances", :force => true do |t| t.string "comment" t.datetime "created_at", :null => false t.datetime "updated_at", :null => false t.integer "user_id" t.integer "event_id" t.integer "position" end ここまでが既存の設計。 ポイント:結局、RDBの設計をちゃんとすれば答えは見えてくる! shuffleの入れ方 その1 attendancesのpositionを生成するという考え方。(Filtered Subresource パターン) /events/1/attendances/positionとか? 部分集合として、レコードを抽出するというよりも、縦にカラムを抽
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