Rails - Aug 2009 - Strange Active::Record behavior, StatementInvalid exception thrown twice?

Hi,

I''m a bit puzzled with an ActiveRecord::StatementInvalid exception
that''s apparently being thrown twice.

I''m using Rails 2.3.3 and Postgres, and inside the Feed Model I have
something like:

has_many :entries, :dependent => :delete_all

def process_feed
  ...
  process_feed_entries
  # log saving feed
  save! # will fail if an exception is thrown below
end

def process_feed_entries
  ...
  begin
    # log saving entry
    entry.save!  # can fail because of duplicate key values
  rescue ActiveRecord::StatementInvalid => e
    # log exception caught
    # log the error in the db (Log Model)
  end
end

DB log:

* Saving entry
BEGIN
PGError: ERROR: duplicate key value ... : INSERT INTO "entries" ...
ROLLBACK
* Exception caught
BEGIN
INSERT INTO "logs" ...
COMMIT
* Saving feed
BEGIN
UPDATE "feeds" ...
PGError: ERROR: duplicate key value ... : INSERT INTO "entries"
ROLLBACK
ActiveRecord::StatementInvalid: PGError: ERROR:  duplicate key ...
Stack trace

The last exception that terminates execution was (or should have been)
caught inside the begin/rescue block. Why is it thrown again when the
feed is saved, if the transaction was rolled back?

Any hints much appreciated!

Thanks,

--
Adriano

On Aug 26, 11:56 am, Adriano Nagel
<a...-pZDOhbmk9TnQT0dZR+AlfA@public.gmane.org>
wrote:
> has_many :entries, :dependent => :delete_all
>   save! # will fail if an exception is thrown below
Nothing like explaining your problem to others :-)

I figure feed.save tries to save the associated entry and that throws
the exception again.

I have to delete the offending entry inside the rescue clause.

Thanks,

--
Adriano

On Aug 26, 3:56 pm, Adriano Nagel
<a...-pZDOhbmk9TnQT0dZR+AlfA@public.gmane.org>
wrote:
> Hi,
>
> I''m a bit puzzled with an ActiveRecord::StatementInvalid exception
> that''s apparently being thrown twice.
>
> I''m using Rails 2.3.3 and Postgres, and inside the Feed Model I
have
> something like:
>
> has_many :entries, :dependent => :delete_all
>
> def process_feed
>   ...
>   process_feed_entries
>   # log saving feed
>   save! # will fail if an exception is thrown below
> end
>
> def process_feed_entries
>   ...
>   begin
>     # log saving entry
>     entry.save!  # can fail because of duplicate key values
Is entry a member of the entries collection ? If so then the docs on
associations state

"All unsaved (new_record? == true) members of the collection are
automatically saved when the parent is saved."
ie when you call feed.save! unsaved association members are saved.

Fred
>   rescue ActiveRecord::StatementInvalid => e
>     # log exception caught
>     # log the error in the db (Log Model)
>   end
> end
>
> DB log:
>
> * Saving entry
> BEGIN
> PGError: ERROR: duplicate key value ... : INSERT INTO "entries"
...
> ROLLBACK
> * Exception caught
> BEGIN
> INSERT INTO "logs" ...
> COMMIT
> * Saving feed
> BEGIN
> UPDATE "feeds" ...
> PGError: ERROR: duplicate key value ... : INSERT INTO "entries"
> ROLLBACK
> ActiveRecord::StatementInvalid: PGError: ERROR:  duplicate key ...
> Stack trace
>
> The last exception that terminates execution was (or should have been)
> caught inside the begin/rescue block. Why is it thrown again when the
> feed is saved, if the transaction was rolled back?
>
> Any hints much appreciated!
>
> Thanks,
>
> --
> Adriano

On Aug 26, 7:39 pm, Frederick Cheung
<frederick.che...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> On Aug 26, 3:56 pm, Adriano Nagel
<a...-pZDOhbmk9TnQT0dZR+AlfA@public.gmane.org> wrote:
>
> Is entry a member of the entries collection ? If so then the docs on
> associations state
>
>
Oops, you beat me to it !

Fred