Transaction block still sets id on model/new_record to false on rollback


#1

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

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?


#2

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.


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