Forum: Ruby on Rails Transaction block still sets id on model/new_record to false on rollback

Announcement (2017-05-07): www.ruby-forum.com is now read-only since I unfortunately do not have the time to support and maintain the forum any more. Please see rubyonrails.org/community and ruby-lang.org/en/community for other Rails- und Ruby-related community platforms.
Farrel (Guest)
on 2009-02-12 02:57
(Received via mailing list)
I'm on Rails 2.2.2 on MySQL with InnoDB table types. I'm running into
a wierd bug where if I have two models in a transaction and the second
model raises an exception, the first model still has it's ID set and
it's new_record status set to false despite the row the ID is set to
never existing.

The following is a console session showing this:

>> client_user = new_client_user( :first_name => nil ) # Will cause validation to fail
=> #<ClientUser id: nil, login: "rene173744", email_address:
"removed_email_address@domain.invalid", first_name: nil, last_name: "Sim", 
active: true>
>> establishment = new_establishment( :brand => brand )
=> #<Establishment id: nil, brand_id: 4, name: "Pretoria GrandWest",
active: true>
>> Establishment.transaction{ establishment.save!; client_user.save!  } rescue false
=> false
>> establishment.id
=> 10
>> establishment.new_record?
=> false
>> client_user.id
=> nil
>> establishment.reload
ActiveRecord::RecordNotFound: Couldn't find Establishment with ID=10
<snip>
>> Establishment.count
=> 4

Here's an explanation of the session:
1) I initialise a new client user, with first_name set to nil so it
will fail a validation
2) I then initialise a new establishment model
3) I try and save both in a transaction block. The client_user.save!
call raises an exception causing the block to roll back.
4) Yet establishment has an ID set to 10 and is marked as not being a
new record.
5) As expected client_user has no ID
6) Calling reload on establishment throws an error because the row
does not exist
7) Counting up the actual rows we see it is below the ID assigned to
establishment (I did this a few times, the first time the assigned ID
was 5, then 6, then 7 etc)

Am I missing something or is this expected behaviour?
Mark Reginald J. (Guest)
on 2009-02-13 11:13
(Received via mailing list)
Farrel wrote:
> I'm on Rails 2.2.2 on MySQL with InnoDB table types. I'm running into
> a wierd bug where if I have two models in a transaction and the second
> model raises an exception, the first model still has it's ID set and
> it's new_record status set to false despite the row the ID is set to
> never existing.

Yes, that's the way Transactions (now) work.

The correct way to handle this is to not proceed with
a transaction unless all model instances being saved
in that transaction have been validated.

The alternative is to wrap rollback_active_record_state!
blocks around the transaction for all instances being
saved except the last.

--
Rails Wheels - Find Plugins, List & Sell Plugins -
http://railswheels.com
This topic is locked and can not be replied to.