Rails migration: best way to retrieve current migration version

Question

Is there good way to retrieve migration version number?

I need to implement a method in a model which behave differently on and beyond a specific migration version.

Answer 1

Rails 5.2 and higher:

> ApplicationRecord.connection.migration_context.current_version
   (0.3ms)  SELECT "schema_migrations"."version" FROM "schema_migrations" ORDER BY "schema_migrations"."version" ASC
=> 20200510093804

> ApplicationRecord.connection.migration_context.get_all_versions
   (0.3ms)  SELECT "schema_migrations"."version" FROM "schema_migrations" ORDER BY "schema_migrations"."version" ASC
=> [20191005164928,
    20191006111502,
   ...

 
Rails up to 5.1.7:

> ActiveRecord::Migrator.current_version
   (0.2ms)  SELECT "schema_migrations"."version" FROM "schema_migrations" 
=> 20120110085802

> ActiveRecord::Migrator.get_all_versions
   (0.3ms)  SELECT "schema_migrations"."version" FROM "schema_migrations" 
=> [20111114121610,
    20111115091108,
   ...