1.
You are using the wrong method. If you want the query always you call it
you should use #load
2.
Using #load you will know exactly when the query is done
3.
#sum with block is not recommended since it will load all the object in
memory. This is why it was deprecated.
The query method is there. It is called #load now.
Rafael Mendonça França
http://twitter.com/rafaelfranca
https://github.com/rafaelfranca
On Wed, Feb 27, 2013 at 6:42 AM, Will Bryant <[email protected]> wrote:
> Hi guys,
>
> I don't think that the changes made to the behavior of #all in 4.0 are a
> very good idea.
>
> I can see that you no longer need to call all in as many cases as you did
> before - that's fine, just don't call it if you don't want it. But that
> doesn't mean you never need it or that people who do need it should not
> have it available.
>
> 1. Yes you can use to_a in many cases, but it behaves differently - for
> example if you have an association, to_a will return the cached target if
> the association has already been loaded. You absolutely need a way to run
> an actual query when you want the latest results. to_a cannot be relied
> upon to do this in all cases.
>
> Note lack of a second query:
>
> irb(main):006:0> p = Project.first
> Project Load (0.2ms) SELECT "projects".* FROM "projects" ORDER BY
> "projects"."id" ASC LIMIT 1
> => #<Project id: 1, created_at: "2013-02-27 09:38:49", updated_at:
> "2013-02-27 09:38:49">
> irb(main):007:0> p.tasks.to_a
> Task Load (0.2ms) SELECT "tasks".* FROM "tasks" WHERE
> "tasks"."project_id" = ? [["project_id", 1]]
> => [#<Task id: 1, project_id: 1, created_at: "2013-02-27 09:38:52",
> updated_at: "2013-02-27 09:38:52">, #<Task id: 2, project_id: 1,
> created_at: "2013-02-27 09:38:53", updated_at: "2013-02-27 09:38:53">]
> irb(main):008:0> p.tasks.to_a
> => [#<Task id: 1, project_id: 1, created_at: "2013-02-27 09:38:52",
> updated_at: "2013-02-27 09:38:52">, #<Task id: 2, project_id: 1,
> created_at: "2013-02-27 09:38:53", updated_at: "2013-02-27 09:38:53">]
> irb(main):010:0> p.tasks.all
> DEPRECATION WARNING: Relation#all is deprecated. If you want to eager-load
> a relation, you can call #load (e.g. `Post.where(published: true).load`).
> If you want to get an array of records from a relation, you can call #to_a
> (e.g. `Post.where(published: true).to_a`). (called from irb_binding at
> (irb):10)
> => [#<Task id: 1, project_id: 1, created_at: "2013-02-27 09:38:52",
> updated_at: "2013-02-27 09:38:52">, #<Task id: 2, project_id: 1,
> created_at: "2013-02-27 09:38:53", updated_at: "2013-02-27 09:38:53">]
> irb(main):011:0> p.tasks.all
> DEPRECATION WARNING: Relation#all is deprecated. If you want to eager-load
> a relation, you can call #load (e.g. `Post.where(published: true).load`).
> If you want to get an array of records from a relation, you can call #to_a
> (e.g. `Post.where(published: true).to_a`). (called from irb_binding at
> (irb):11)
> => [#<Task id: 1, project_id: 1, created_at: "2013-02-27 09:38:52",
> updated_at: "2013-02-27 09:38:52">, #<Task id: 2, project_id: 1,
> created_at: "2013-02-27 09:38:53", updated_at: "2013-02-27 09:38:53">]
>
> 2. It's very important that queries run at the point you think they do in
> any application that uses locks or concurrency. Again, if you don't use
> locks or concurrency, fine - don't call the query methods. But many people
> do and they need to be able to run the queries to make this work.
>
> 3. It's not true that you no longer need to care whether you have an array
> or a relation. For example, methods like sum with a block need arrays, as
> the deprecation makes clear:
>
> irb(main):009:0> p.tasks.sum(&:id)
> DEPRECATION WARNING: Calling #sum with a block is deprecated and will be
> removed in Rails 4.1. If you want to perform sum calculation over the array
> of elements, use `to_a.sum(&block)`. (called from irb_binding at (irb):9)
> Task Load (0.1ms) SELECT "tasks".* FROM "tasks" WHERE
> "tasks"."project_id" = ? [["project_id", 1]]
> => 3
>
> 4. It's true that making all basically useless means you can now call all
> on a model class itself and get a relation and then you can merge that or
> whatever, which was one of the other examples in the changelog. But you
> could do that already - using scoped. It is not necessary to break #all's
> behavior to get this functionality.
>
> Have I misunderstood the change?
>
> If not, can we please put back the query method? Running queries is a
> pretty core responsibility of ActiveRecord.
>
> Thanks,
> Will
>
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