更改：项目排行榜使用数据存储以及数据导出的功能

app/models/daily_project_statistic.rb

@@ -0,0 +1,28 @@
+# == Schema Information
+#
+# Table name: daily_project_statistics
+#
+#  id           :integer          not null, primary key
+#  project_id   :integer
+#  date         :string(255)
+#  visits       :integer          default("0")
+#  watchers     :integer          default("0")
+#  praises      :integer          default("0")
+#  forks        :integer          default("0")
+#  issues       :integer          default("0")
+#  pullrequests :integer          default("0")
+#  commits      :integer          default("0")
+#  created_at   :datetime         not null
+#  updated_at   :datetime         not null
+#
+# Indexes
+#
+#  index_daily_project_statistics_on_date        (date)
+#  index_daily_project_statistics_on_project_id  (project_id)
+#
+
+class DailyProjectStatistic < ApplicationRecord
+
+
+  belongs_to :project
+end