Question about a rails behaviour

Rails
1

Hello, my doubt is the following. The line of code below fetches all
the comments made for an specific event:

@comments = @event.event_comments.paginate(:all, :include =>
[:comment_by], :order => "created_at DESC", :page =>
params[:page], :per_page => 10)

As you can see it has a :include => [:comment_by] to include the name
of the user who made the comment.

event_comment model

belongs_to :comment_by, :select => "id, name, lastname", :foreign_key
=> :commentator_id, :class_name => "User"

On my views I have a partial that loops the comments and contains code
similar to this:

comment.comment_by.name

So my question is:

If I don’t put the include on the find method and let the views as
they are, does rails make a new query when it sees something like
comment.comment_by.name. And if that is the case, if I put the include
on the find, am I saving those queries from happening for each comment
later on?

Thanks,

Elioncho

2

On Wed, Jul 23, 2008 at 12:04 PM, elioncho [email protected] wrote:

As you can see it has a :include => [:comment_by] to include the name

comment.comment_by.name

So my question is:

If I don’t put the include on the find method and let the views as
they are, does rails make a new query when it sees something like
comment.comment_by.name.

Yes. Rails will automatically query the database if you request an
association that is not already loaded.

And if that is the case, if I put the include

on the find, am I saving those queries from happening for each comment
later on?

Yes. You can also verify what SQL queries rails is executing by
looking in the log files.