ruby-on-rails - 如何在 Rails 上查找数据库迁移日志？

Question

我想使用 STEP 参数将我的数据库回滚到 Rails 上的某个版本，但我不知道我应该回滚多少步，所以我想检查迁移日志。我可以在 Rails (v3.2.13) 上这样做吗？

Answer 1

尝试以下操作：

rake db:migrate:status

它将为您提供以下输出，up表示迁移已运行，down尚未运行：

Status   Migration ID    Migration Name
--------------------------------------------------
   up     20120328154345  Devise create users
   up     20120331182021  Create websites

Answer 2

You can try to get migration versions by

 >  ActiveRecord::Migrator.current_version
   (38.7ms)  SELECT "schema_migrations"."version" FROM "schema_migrations" 
 => 20130403113845 
1.9.3-p392 :002 > ActiveRecord::Migrator.get_all_versions
   (0.8ms)  SELECT "schema_migrations"."version" FROM "schema_migrations" 
 => [20130327085819, 20130327085820, 20130327085821, 20130327085822, 20130327085823, 20130327085824, 20130327085825, 20130327085826, 20130327085827, 20130327085828, 20130327085829, 20130327085830,........

or you can use the time stamp of the specific migration upto which you want to rollback and use

rake db:migrate:down VERSION= timestamp