ActiveRecord::Base.connection.execute is exec?

Rails
1

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.

2

On Dec 4, 2:59am, tamagohan [email protected] 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

3

On 12月5日, 午前5:18, Frederick C. [email protected] wrote:

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

4

On Dec 5, 12:59 am, tamagohan [email protected] wrote:

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

5

Thanks, Fred!
I misunderstood…

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

Masaki
2011/12/05 20:09 “Frederick C.” [email protected]: