Question

I just changed my DB from mysql to postgres and I’m getting the following error:

ActionView::Template::Error (PG::Error: ERROR:  operator does not exist: character varying = integer
LINE 1: ...ELECT COUNT(*) FROM "agents"  WHERE "agents"."client_id" = 1

when doing

client.agents.count

I have a Data is structured as follows: Clients have several Agents, and can only add more Agents if agents.count < X, so I’m using something like client.agents.count to retrieve this value and compare, but I’m getting that error. Do I need to use manual sql to get this done? Or am I missing something stupid?

Thank you for your comments

MODEL INFO

class Agent < User

  belongs_to :client
  attr_accessible :client_id

  validates :client_id, presence: true


end

class Client < User
  attr_accessible :appId, :expire_date, :legacy, :url, :plan_id, :chat_window_color, :chat_head_color, :chat_box_container_color, :chat_box_color, :tab_message, :greeting, :please_wait_message, :send_message_button, :comments_label, :offline_message

  belongs_to :plan
  has_many :agents, :dependent => :destroy

  has_secure_password

  after_initialize :init

  #omited validations

  private
  #BEGIN PRIVATE METHODS
end

Both inherit from user

class User < ActiveRecord::Base
    self.abstract_class = true

  attr_accessible :email, :name, :password, :password_confirmation

  attr_accessor :updating_password

  has_secure_password

  before_save { self.email.downcase! }

  #the controller must set updating_password to FALSE to avoid validation
  def should_update_password?
    updating_password || new_record?    
  end

end

Answer 1

So I found the issue, the column client_id is a varchar and mysql allowed this but postgres complained about the different datatypes. Got a mgiration working by doing something like this:

def up
  rename_column :agents, :client_id, :client_id_old
  add_column :agents, :client_id, :integer
  Agent.reset_column_information
  Agent.find_each { |c| c.update_attribute(:client_id, c.client_id_old) } 
  remove_column :agents, :client_id_old
end

From this link How do I change column type in Heroku?.

---

To avoid the issues when changing datatypes in postgres directly with change_column. Hope this helps someone else