How to create records into table with generated 'as identity' primary key?

[gavvvr]

Steps to reproduce

So I have Oracle v12 which means I can use as identity in column definition to get autogenerated id. I have the following table:

create table t_text_file
(
    text_file_id number(12) generated always as identity
        constraint t_text_file_pk
            primary key,
    name         varchar2(20),
    data         clob
)

My model is:

module Database
  class TextFile < ActiveRecord::Base
    self.table_name = 't_text_file'
    self.primary_key = 'text_file_id'
    # self.sequence_name = :autogenerated
  end
end

The code I execute is:

Database::TextFile.create(name: 'file.csv', data: "line1\nline2")

Expected behavior

Database insert without errors

Actual behavior

I get the following error:

OCIError: ORA-02289: sequence does not exist

What is going on in logs at the same time:

D, [2020-09-14T19:17:12.205496 #52369] DEBUG -- : next sequence value (113.6ms) SELECT "T_TEXT_FILE_SEQ".NEXTVAL FROM dual

It tries guess sequence name T_TEXT_FILE_SEQ and use it.

If I uncomment self.sequence_name = :autogenerated, the error is:

ArgumentError: Trigger based primary key is not supported

Obviously I am not trying to use trigger. I just want to disable using sequence and rely on a new mechanism of using Identity available from Oracle 12. I see the change comes from #1669, :autogenerated can not be used anymore since 6.x. But how am I supped to use as identity columns? self.sequence_name = :autogenerated will not work too and will lead to null pointer error.

System configuration

I use ActiveRecord without Rails:

gem 'activerecord', '~> 6.0.3', :require => "active_record"

Oracle enhanced adapter version:

gem 'activerecord-oracle_enhanced-adapter', '~> 6.0.4'

Ruby version:

2.6.6

Oracle Database version:

Oracle Database 12c Enterprise Edition Release 12.1.0.2.0

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[yahonda]

As of right now, Oracle enhanced adapter does not support identity data type then it should not work. There was a plan to support it but did not have enough time/motivation to implement it.