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优化以下代码

ruby-1.9.3 ruby-on-rails-3.2 ruby-on-rails-3 ruby ruby-on-rails

0

user2906085 · 技术社区 · 12 年前

我有两个活动记录 StudentDemographics 和 StudentWeeklyReport 两者都有 has_many 关系如下:

class StudentDemographics < ActiveRecord::Base
  has_many :student_weekly_reports, :foreign_key => :student_id
end

我必须在最后一次第五周的研讨会上与最近一次的研讨会核对每个学生的分数。如果结果是 true ,学生应该活跃,否则就不活跃。我有以下代码。在这里,我重复每个日期的循环。 @distinct 是一个日期数组。

 for i in 0...@distinct.length
     active = 0
     inactive = 0
     sum = safe.length
     @students = StudentDemographics.where("date <= ?", @distinct[i]).select("student_id") - safe
     @students.each do |student|
        @stu = StudentWeeklyReport.where(:student_id => student.student_id).select("student_id,golden_eggs").last(5)
            if @stu.length > 4
                if @stu[4].golden_eggs > @stu[0].golden_eggs
                  safe << student
                  active += 1
                else
                  inactive += 1
                end
            else
                safe << student
                active += 1
            end
      end
      @active[i] = active + sum
      @inactive[i] = inactive
end

性能不好。它需要超过3秒的时间。my-mysql-db有13600英寸 StudentWeeklyReports 表和2000英寸 学生人口统计 桌子有人能建议如何优化以下代码吗?

2 回复 | 直到 12 年前

1

Thaha kp 12 年前

     @students = StudentDemographics.includes(:student_weekly_reports) - safe
 for i in 0...@distinct.length
     active = inactive = 0
     @students.each do |student|
        next if student.date > @distinct[i]
        @stu = student.student_weekly_reports.select("golden_eggs").last(5)
            if @stu.length > 4 && (@stu[4].golden_eggs <= @stu[0].golden_eggs)
                inactive += 1
            else
                safe << student
                active += 1
            end
      end
      @active[i] = active + safe.length
      @inactive[i] = inactive
end

2

0

Amit Thawait 12 年前

@students = StudentDemographics.includes(:student_weekly_reports).where("date <= ?", @distinct.min).select("student_id")
# The above line will fetch all the necessary records you require 

for i in 0...@distinct.length
 active = inactive = 0
 @students = @student.select { |student_demographics| student_demographics.date <= @distinct[i] } - safe
 @students.each do |student|
   @stu = student.student_weekly_reports.select("golden_eggs").last(5)
   if @stu.length > 4 and (@stu[4].golden_eggs <= @stu[0].golden_eggs)
     inactive += 1
   else
     safe << student
     active += 1
   end
  end
  @active[i] = active + safe.length
  @inactive[i] = inactive
end