修改迁移文件

db/migrate/20200518092612_change_project_watchers_count.rb

@@ -1,11 +1,12 @@
 class ChangeProjectWatchersCount < ActiveRecord::Migration[5.2]
+  #修改project的watchers_count 不正确的问题
   def change
     watcher_ids = Watcher.where(watchable_type: "Project").pluck(:watchable_id).uniq 
     watcher_ids.each do |i|
       puts "#######____update_project_watchers_id____##############{i}"
       p = Project.includes(:watchers).select(:id, :watchers_count).find_by(i) 
       if p.present?
-        p.update_attribute(:watchers_count, p.watchers.size)
+        Project.reset_counters(i, :watchers)
       end
     end
   end