迁移文件

db/migrate/20190329070441_migrate_homework_common_end_times.rb

@@ -0,0 +1,14 @@
+class MigrateHomeworkCommonEndTimes < ActiveRecord::Migration
+  def up
+    homework_commons = HomeworkCommon.where("id < 21549")
+    homework_commons.find_each do |homework|
+      sql = "update homework_commons set end_time = (select max(end_time) from
+        homework_seconds where id = #{homework.id}) where id = #{homework.id}"
+
+      ActiveRecord::Base.connection.execute(sql)
+    end
+  end
+
+  def down
+  end
+end