时间课程问题

lib/tasks/statistic_subject_info.rake

@@ -7,11 +7,9 @@ namespace :subjects do
     subjects = Subject.where(status: 2, hidden: 0)
     column_value = "subject_id, study_count, course_study_count, initiative_study, passed_count, course_used_count, " +
         "school_used_count, created_at, updated_at"
-    buffer_size = 0
-    str = []
     subjects.find_in_batches(batch_size: 50) do |s|
+      str = []
       Parallel.each_with_index(s, in_processes: 4) do |subject, index|
-        buffer_size += 1
         puts("---------------------data_statistic: #{subject.id}")
         Rails.logger.info("---------------------data_statistic: #{subject.id}")
         data = Subjects::DataStatisticService.new(subject)
@@ -29,7 +27,6 @@ namespace :subjects do
           puts sql
           ActiveRecord::Base.connection.execute sql
           str = []
-          buffer_size = 0
         end
       end
     end