调整

db/migrate/20191026110116_migrate_chart_rule.rb

@@ -3,7 +3,7 @@ class MigrateChartRule < ActiveRecord::Migration[5.2]
     ChartRule.all.each do |rule|
       if rule.competition
         com_module = rule.competition.competition_modules.find_by(module_type: "chart")
-        if com_module
+        if com_module && !com_module.competition_module_md_contents.exists?(competition_stage_id: rule.competition_stage_id ? rule.competition_stage_id : 0)
           CompetitionModuleMdContent.create!(content: rule.content, competition_module_id: com_module.id, competition_stage_id: rule.competition_stage_id ? rule.competition_stage_id : 0)
         end
       end