CODEWITHSUNDEEP
ruby-on-railsruby-on-rails-3activerecord
stewart715
stewart715

Reputation: 5637

getting ID of activerecord model

Current Code

@current_site_name = 'SITENAME'
@current_site = Site.where(:name => @current_site_name)
@current_site_id = @current_site.id

Basically, the name column in our Site model is unique. We are selecting a row using the site name as a parameter.

I am returned: <ActiveRecord::Relation:0x59426bc1>

I understand that I cannot simply ask for @current_site.id but is there any way to put the ID of the single activerecord into the variable @current_site_id

Again, there will always be one active record.

Upvotes: 1

Views: 2988

Answers (3)

BaronVonBraun
BaronVonBraun

Reputation: 4293

Just to throw another solution out there, you can make use of Rails' dynamic finders that are created for your models.

@current_site = Site.find_by_name(@current_site_name)

This returns a single record (and thus doesn't require the use of first) and might be seen as cleaner code in some people's opinion.

Upvotes: 0

Igbanam
Igbanam

Reputation: 6082

Hmm... This is quite strange.

Site.where(:name => @current_site_name).methods.include? :id #=> false

but

Site.where(:name => @current_site_name).instance_methods.include? :id #=> true

However,

Site.where(:name => @current_site_name).instance_eval "id" #=> NameError

and

Site.where(:name => @current_site_name).methods.include? "self.id" #=> NoMethodError

That said, a workaround assuming in your case, only one record should be returned is

Site.where(:name => @current_site_name).instance_eval('find_first').id

The find_first method is protected so we have to jump scope in its execution to avoid another NoMethodError

Upvotes: 0

Rachel Shallit
Rachel Shallit

Reputation: 2020

As you've seen, where will return an ActiveRecord::Relation (a set of rows), even if there's only one row that matches your criteria. You can make @current_site be assigned to the row you want by changing the line to this:

@current_site = Site.where(:name => @current_site_name).first

Upvotes: 3

Related Questions