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我正在嘗試查找在給定時間段內註冊到ActionMovie計劃的所有用戶。我遇到了N + 1問題，並且花了很長時間纔得到新註冊數量。我想知道是否有任何創新的東西，我可以用arel_tables或類似的東西，可以幫助減少這個過程？任何建議表示讚賞！我當前的代碼看起來類似於下面：單表繼承N + 1問題的Rails mysql查詢
#find all UserMovies created during time frame
user_movies = UserMovie.where(:created_at => start_time..end_time)
#find users
users = user_movies.collect {|um| um.user}
#iterate through each users user_movies and see if the their first action movie was during the time frame I am looking for
users.each do |user|
user_movies_array = user.user_movies.map {|um| {um.movie.type => um.created_at}}
user_movies_array.each do |um|
if um["ActionMovie"] > start_time
puts "new user"
end
end
end
Class User
has_many :user_movies
has_many :movies, :through => :user_movies
end
Class Movie
has_many :user_movies, :foreign_key => :movie_id
has_many :users, :through => :user_movies
end
Class UserMovie
belongs_to :user
belongs_to :movie
end
Class ActionMovie < Movies
end
Class SuspenseMovie < Movies
end