Cannot add new enum value about activerecord-pg_enum HOT 2 CLOSED

Hi! The error message is telling you whats wrong. Here's the important bit: cannot run inside a transaction block

It may not be obvious if you're not familiar with Rails migrations. Every migration runs inside a DB transaction by default. Sometimes that's invalid, like when you're building a concurrent index or in this case altering an enum.

Here's the relevant documentation from PostgreSQL:

ALTER TYPE ... ADD VALUE (the form that adds a new value to an enum type) cannot be executed inside a transaction block.

Here's what you should do:

class AddNewValue < ActiveRecord::Migration[5.1]
  disable_ddl_transaction!

  def change
    add_enum_value :my_test_enum, 'FOO', before: 'BAR'
  end
end

I'll update the documentation to make this more clear.

from activerecord-pg_enum.

Nice, it work! thank for your answer!

from activerecord-pg_enum.