ROR - Loop through active record result and form an array

Question

I am trying to form an array from the result I got from querying the database

industries = Industry.find_by_name(j['Categories']).industries

The result that i get is as following

[#<Industry id: 3717, staffroom_type: "Industry", name: "Home Service", created_at: "2016-01-19 02:33:30", updated_at: "2016-01-19 05:25:53", parent_id: nil, user_cannot_join_shortlists: false, location: "SYDNEY, NSW, 2000", latitude: -33.8674769, longitude: 151.2069776, shortlist_introduction_email_subject: nil, shortlist_introduction_email_body: nil, external_job_url_enabled: false, deleted: false, deleted_at: nil, account_id: 3506, create_group_permission: false, create_role_permission: false, edit_group_permission: true, uuid: "70ef9351-f517-40a9-a300-8c1078da033a", staffroom_image_file_name: nil, staffroom_image_content_type: nil, staffroom_image_file_size: nil, staffroom_image_updated_at: nil, staffroom_image_repository: "production", cached_staffroom_image_id: nil, industry_type_id: nil, company_id: nil, billed_to: "employer", admin_user_id: nil, send_job_notifications: true, do_not_feature_jobs: false, company_type: nil, company_type_other: nil, company_restriction: nil, shortlist_count: nil>,
 #<Industry id: 1624, staffroom_type: "Industry", name: "Aged and Disability Care", created_at: "2015-04-13 02:07:53", updated_at: "2017-05-30 10:49:17", parent_id: nil, user_cannot_join_shortlists: false, location: "NOT PROVIDED (Assuming Sydney, 2000)", latitude: nil, longitude: nil, shortlist_introduction_email_subject: nil, shortlist_introduction_email_body: nil, external_job_url_enabled: false, deleted: false, deleted_at: nil, account_id: 3506, create_group_permission: false, create_role_permission: false, edit_group_permission: true, uuid: "f4b7bac3-3587-4056-a88f-9a9e98c42197", staffroom_image_file_name: nil, staffroom_image_content_type: nil, staffroom_image_file_size: nil, staffroom_image_updated_at: nil, staffroom_image_repository: "production", cached_staffroom_image_id: nil, industry_type_id: nil, company_id: nil, billed_to: "employer", admin_user_id: nil, send_job_notifications: true, do_not_feature_jobs: false, company_type: nil, company_type_other: nil, company_restriction: nil, shortlist_count: nil>]

I would like to convert this result into an array that just looks like this

['Home Service', 'Aged and Disability Care']

These are the name of industries that i get from database.

This is what i tried

      industries.each do |industry|
        ind[] = industry['name']

      end

but I get an error

NoMethodError: undefined method `each' for #

What am I doing wrong here?

This is what j['Categories'] looks like

Disability Support Worker: Disability Support Worker

Quick question - if you're using find_by_name or where(name: ...) from j['Categories'] and looking to select the industry's name... could you not just use the value of j['Categories']? (If not, @Jordan has the right answer) :) — SRack
– SRack, Commented May 30, 2017 at 16:40

Jordan Running · Accepted Answer · 2017-05-30 16:38:18Z

4

Use the built-in pluck method:

Industry.where(name: j['Categories']).pluck(:name)

This will be much more performant than map: The map solution will retrieve every column and instantiate an Industry object for each record, then call the name method on each object. pluck will retrieve only the given column and return an array of strings.

answered May 30, 2017 at 16:38

Jordan Running

107k18 gold badges193 silver badges189 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Jordan Running Over a year ago

Dear downvoter: Please take a moment to leave a comment explaining the reason for your downvote. If my answer is lacking I'd appreciate the opportunity to improve it.

Collectives™ on Stack Overflow

ROR - Loop through active record result and form an array

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related