Question

I am getting error like

Mysql2::Error: Unknown column 'ctr' in 'having clause': SELECT COUNT(*) AS count_all, artists.id AS artists_id FROM `artists` INNER JOIN `photos` ON `photos`.`photoable_id` = `artists`.`id` AND `photos`.`photoable_type` = 'Artist' WHERE (admin_approved = 1) GROUP BY artists.id HAVING ctr >= 2

My artist model I write scope

scope :approved, where("admin_approved = ?", true)
scope :completed_profile, joins(:photos).select("artists.*,count(photos.id) as ctr").group("artists.id").having("ctr >= 2")

In my controller I write

  def artists_completed_profile
     @artists = Artist.approved.completed_profile.page(params[:page]).per(10)
     @total_artists = @artists.size
  end 

Note: When I try in my console then I am not getting any error but when I write in model or controller then I am getting this error.

Thanks In Advance

Answer 1

Something in your pagination is doing a .count, most likely when it tries to figure out the total number of matches and thus the total number of pages. That .count will ignore the .select part of your scope, that’s why you’re seeing:

SELECT COUNT(*) AS count_all, artists.id AS artists_id ...

being sent to MySQL. Your ctr alias is defined by your .select so the .count‘s SQL fails. You should be able to get around this problem by not using ctr in your HAVING, just use the raw count(photos.id):

scope :completed_profile, ...having("count(photos.id) >= 2")