ActiveRecord::Base.connection.execute is exec?

[tamagohan]

Hi all, I update column by 'ActiveRecord::Base.connection.execute'
ActiveRecord::Base.connection.execute "UPDATE requests SET count=count
+10 WHERE id=1 AND count <= 1000"
But, I can't know if condition,..'count <= 1000' is met
How can I know if condtion is met?

Please in mind, any other process very often update count, not only
add but also subtract

appreciate any help.
Thank you
Masaki.

[Frederick Cheung]

On Dec 4, 2:59 am, tamagohan <takahashi...@gmail.com> wrote:
> Hi all, I update column by 'ActiveRecord::Base.connection.execute'
> ActiveRecord::Base.connection.execute "UPDATE requests SET count=count
> +10 WHERE id=1 AND count <= 1000"
> But, I can't know if condition,..'count <= 1000' is met
> How can I know if condtion is met?
>

I think that if you use update rather than execute you'll get the
number of modified rows returned.

Fred

[tamagohan]

On 12月5日, 午前5:18, Frederick Cheung <frederick.che...@gmail.com> wrote:
> On Dec 4, 2:59 am, tamagohan <takahashi...@gmail.com> wrote:> Hi all, I update column by 'ActiveRecord::Base.connection.execute'
> > ActiveRecord::Base.connection.execute "UPDATE requests SET count=count
> > +10 WHERE id=1 AND count <= 1000"
> > But, I can't know if condition,..'count <= 1000' is met
> > How can I know if condtion is met?
>
> I think that if you use update rather than execute you'll get the
> number of modified rows returned.
>
> Fred
>

Thanks!
but sorry...

I want to use execute.
Because, I feared race condition.
For example,
process A get count,...100
process B get count,...100
process A update count to (count + 10),...110
process B update count to (count + 10),...110
But, after 2 proceess, count should be 120.

So, I update count by database, not by application.

Masaki

[Frederick Cheung]

On Dec 5, 12:59 am, tamagohan <takahashi...@gmail.com> wrote:
> On 12月5日, 午前5:18, Frederick Cheung <frederick.che...@gmail.com> wrote:
>
> > On Dec 4, 2:59 am, tamagohan <takahashi...@gmail.com> wrote:> Hi all, I update column by 'ActiveRecord::Base.connection.execute'
> > > ActiveRecord::Base.connection.execute "UPDATE requests SET count=count
> > > +10 WHERE id=1 AND count <= 1000"
> > > But, I can't know if condition,..'count <= 1000' is met
> > > How can I know if condtion is met?
>
> > I think that if you use update rather than execute you'll get the
> > number of modified rows returned.
>
> > Fred
>
> Thanks!
> but sorry...
>
> I want to use execute.

You've misunderstood me. I meant se
ActiveRecord::Base.connection.update "..."
which is the same as update except that you get the altered row count
(and also clears rails' query cache)

Fred

[高橋正樹]

Thanks, Fred!
I misunderstood..

I could get affecyed colmun count.
Thank you so much!

Masaki

2011/12/05 20:09 "Frederick Cheung" <frederic...@gmail.com>:

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