Rails - Oct 2009 - Rails 2.3 Model.touch(:column) always also updates :updated_at???

Hi,

Am I the only one (i.e. something I do is wrong), or does the touch-
method always update updated_at, even though giving it a column to use
INSTEAD is meant to update just that column???

Thanks,

Michael

On Fri, Oct 16, 2009 at 4:57 AM,
michael.hasenstein-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org <
michael.hasenstein-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org> wrote:
>
> Hi,
>
> Am I the only one (i.e. something I do is wrong), or does the touch-
> method always update updated_at, even though giving it a column to use
> INSTEAD is meant to update just that column???
>
> Thanks,
>
> Michael
>
>
Michael, is the attribute that you''re passing to the touch method a
field of
type datetime or date?  If not, then it only makes
sense that field that you''re passing to the touch method is one of
those.

Good luck,

-Conrad

> >
>
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> Michael, is the attribute that you''re passing to the touch method
a field of
> type datetime or date?  If not, then it only makes
> sense that field that you''re passing to the touch method is one of
those.
It is "datetime".

But anyway, just looking at the code for "touch" I can''t see
how it''s
is supposed to NOT always write updated_at - it uses write_attribute
which as far as I found out only changes the in-memory object, there
must be a "save" somewhere else and that goe4s through the usual
validations etc. There''s a lighthouse ticket for "touch"
calling for
it not to do validations (https://rails.lighthouseapp.com/projects/
8994-ruby-on-rails/tickets/2520-patch-activerecordtouch-without-
validations).

In the mean time, can you work around this issue with something like:

Create a separate table with a 1:1 relationship to your current table
Migrate the field you want to touch to the new table.
Touch the field in that table, which will leave the updated_at field
in your original table alone.
You could even make the new table without the timestamps fields, if you wanted.

--wpd

Well, I''m using separate timestamps for associated objects as an aid
for cache-key generation, to avoid throwing out too many cache entries
needlessly. I could look at the updated_at of the associated items
themselves - but guess what, I want to save database queries :-) So
adding another table is not quite the way.
I consider writing my own (SQL-based!) method, especially after
finding out through the lighthouse ticket mentioned previously that
all the validations are called. I have quite a few triggers and
procedures in the database already anyway doing stuff behind rails''
back, I would just like to limit those to certain critical areas, and
a (non-frequent) timestamp update wasn''t on my list of things to do
through trigger rather than through actvierecord.

Thanks,
Michael


On Oct 16, 3:06 pm, Patrick Doyle
<wpds...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
...
> Create a separate table with a 1:1 relationship to your current table
...

So... I put it all into the mySQL triggers now. Saves a lot of
ActiveRecord overhead anyway, and keeps this very low-level issue/
optimization away from the "business logic" of the application.