ActiveRecord::Relation

Rails
1

Hi
I have just started learning Rails3 (ruby1.92, Rails3.0.5) and watched
railscast episode 202. I tried
Article.where(:hidden => true) from console. I have a confusion there
since the cast says that , the above statement execute query in the view
when iterated. I did not understand that. I got result from query in the
console it self when executed Article.where(:hidden => true). Please
comment

Thanks

2

Hi
i am talking exactly about this. Now only I found this

https://rails.lighthouseapp.com/projects/8994/tickets/4476-lazy-loading-broken-since-beta3

  I am getting this not only in console but application also. Has

anything changed in Rails3.0.5?

3

On Apr 7, 8:56am, Tom M. [email protected] wrote:

Hi
I have just started learning Rails3 (ruby1.92, Rails3.0.5) and watched
railscast episode 202. I tried
Article.where(:hidden => true) from console. I have a confusion there
since the cast says that , the above statement execute query in the view
when iterated. I did not understand that. I got result from query in the
console it self when executed Article.where(:hidden => true). Please
comment

The issue is that the console wants to print the result of the
expression you type, which forces ActiveRecord to execute the query.

Fred

4

Hi Fred
Thanks . I tried from sample application also like
def index
@articles = Article.where(:hidden => true)
puts @articles.inspect
-------------
end

  Here also the query executed. I dont know why.
5

On Apr 7, 10:49am, Tom M. [email protected] wrote:

Hi Fred
Thanks . I tried from sample application also like
def index
@articles = Article.where(:hidden => true)
puts @articles.inspect

end

Here also the query executed. I dont know why.

because you called inspect on @articles

Fred

6

On Apr 7, 1:21pm, Tom M. [email protected] wrote:

Hi
Then how can I check that it is not triggering sql. I did not
understand it properly. Could you explain more please?

Look in your development log and ensure that you don’t touch the scope

  • when you do anything other than adding conditions, joins etc. to the
    scope you force active record to evaluate it.

Fred

7

the difference might be illustrated by the following:

Article.where(:hidden => true).to_sql

vs.

Article.where(:hidden => true).all.to_sql

in the first, you are able to get the (currently un-executed) sql
statement

in the second, you will get an undefined_method error because having
been evaluated, you now have an array (or a proxy to an array) instead
of a scope.

does that help?

On Apr 7, 7:59am, Frederick C. [email protected]

8

Hi
Then how can I check that it is not triggering sql. I did not
understand it properly. Could you explain more please?

Frederick C. wrote in post #991438:

On Apr 7, 10:49am, Tom M. [email protected] wrote:

Hi Fred
Thanks . I tried from sample application also like
def index
@articles = Article.where(:hidden => true)
puts @articles.inspect

end

Here also the query executed. I dont know why.

because you called inspect on @articles

Fred