Problem with custom select / PG function

[mbajur]

Hello!
i'm trying to use search_cop with my quite complex model code. Basically, i have a custom postgres function and i'm using it like that:

@users = User.all.select('CUSTOM_FUNCTION(users.id) AS custom_function')
@users.last.id  #=> 1
@users.last.custom_function  #=> "result"

However, when i apply a search_cop method search() to the code above, i'm not able to access my custom_function result row:

@users = User.all.search('query').select('CUSTOM_FUNCTION(users.id) AS custom_function')
@users.last.id  #=> 1
@users.last.custom_function  #=> nil

What's more interesting - i can see that db query produced by the chain above looks quite proper and i'm able to use it in pgAdminII which gives me a custom_function column with the proper value.

Have you any idea what can be wrong in here or what can i do about it?

Thanks in advance.

[mrkamel]

#eager_load doesn't seem to work well with #select:

Product.select("products.id as xyz").last.xyz
=> 1

Product.eager_load(:comments).select("products.id as xyz").last.xyz
=> NoMethodError: undefined method `xyz' for ...

I don't consider this to be a bug in SearchCop as the use of eager_load is clearly stated.

However, to fix it you currently have to do the join-logic yourself via a scope block within your search_scope block and avoid eager_load. Check out https://github.com/mrkamel/search_cop#associations

In case you need help with the join logic, just call.

[mbajur]

Thank you for reply, mrkamel!
I'm affraid i'm not quite comfortable with defining that by myself. Can you please guide me a bit on how to make that? It should later go to the README as an example cause i think it might be quite common issue.

[mrkamel]

Ok, please post your current search_scope and association specifications to let me help you. If your model is the one you already mentioned in issue #5, you should be able to use/switch to my proposed final version of option A) from there.

BTW, there already are examples regarding custom scope's in the README. Moreover, this IMO is more an ActiveRecord issue than a SearchCop issue.

[mbajur]

Yes, that's exactly what i have mentioned in #5 :) Yes, i'm definatelly not denying that it's AR issue rather than SearchCop, i'm just using SearchCop in my production commercial app and this one thing stops me from making a final deploy before a deadline which has passed on friday. That's why i'm kind of desperate and not able to deal with that on my own.

Therefore, i'm 100 times more thankfull for your will to help me with that thing :)

[mrkamel]

So, is #5 sufficient to get the thing done? If not, please post your current search_scope block plus your associations (has_one, belongs_to, ...)

[mbajur]

Oh, sorry, i've made a horrible mistake. I meaned completely different model and the #5 task is completely not relevant. Here is my code:

class User < ActiveModel::Base
  belongs_to :dealership

  search_scope :search do
    attributes :email, :name, :phone, :role
  end
end

Thanks!

[mrkamel]

Hm, your search_scope doesn't search within attributes of an associated model at all. Thus, SearchCop won't eager_load anything. Are you sure your snippet is complete? Maybe post the generated sql for User.all.select('CUSTOM_FUNCTION(users.id) AS custom_function') VS User.all.search('query').select('CUSTOM_FUNCTION(users.id) AS custom_function')

[mbajur]

Sure, here it is:

Without search() method

# User.with_sums.last.total_ro_value

SELECT USER_JOBS_TOTALS('ro_value' :: text, users.*, '1914-10-14' :: text, '2114-10-14' :: text, 'false' :: boolean)       AS total_ro_value, 
       USER_JOBS_TOTALS('final_ro_value' :: text, users.*, '1914-10-14' :: text, '2114-10-14' :: text, 'false' :: boolean) AS total_final_ro_value, 
       USER_JOBS_TOTALS('upsell_value' :: text, users.*, '1914-10-14' :: text, '2114-10-14' :: text, 'false' :: boolean)   AS total_upsell_value 
FROM   "users" 
WHERE  "users"."role" = 'service_technician' 
ORDER  BY "users"."id" DESC 
LIMIT  1 

With search()

# User.with_sums.search('rodrigo').last.total_ro_value

SELECT   USER_JOBS_TOTALS( 'ro_value'::text, users.*, '1914-10-14'::text, '2114-10-14'::text, 'false'::      boolean ) AS total_ro_value, 
        USER_JOBS_TOTALS( 'final_ro_value'::text, users.*, '1914-10-14'::text, '2114-10-14'::text, 'false'::boolean ) AS total_final_ro_value, 
         USER_JOBS_TOTALS( 'upsell_value'::text, users.*, '1914-10-14'::text, '2114-10-14'::text, 'false'::  boolean ) AS total_upsell_value, 
         "users"."id"                                                                                                  AS t0_r0,
         "users"."email"                                                                                               AS t0_r1,
         "users"."encrypted_password"                                                                                  AS t0_r2,
         "users"."reset_password_token"                                                                                AS t0_r3,
         "users"."reset_password_sent_at"                                                                              AS t0_r4,
         "users"."remember_created_at"                                                                                 AS t0_r5,
         "users"."sign_in_count"                                                                                       AS t0_r6,
         "users"."current_sign_in_at"                                                                                  AS t0_r7,
         "users"."last_sign_in_at"                                                                                     AS t0_r8,
         "users"."current_sign_in_ip"                                                                                  AS t0_r9,
         "users"."last_sign_in_ip"                                                                                     AS t0_r10,
         "users"."confirmation_token"                                                                                  AS t0_r11,
         "users"."confirmed_at"                                                                                        AS t0_r12,
         "users"."confirmation_sent_at"                                                                                AS t0_r13,
         "users"."unconfirmed_email"                                                                                   AS t0_r14,
         "users"."failed_attempts"                                                                                     AS t0_r15,
         "users"."unlock_token"                                                                                        AS t0_r16,
         "users"."locked_at"                                                                                           AS t0_r17,
         "users"."authentication_token"                                                                                AS t0_r18,
         "users"."name"                                                                                                AS t0_r19,
         "users"."phone"                                                                                               AS t0_r20,
         "users"."role"                                                                                                AS t0_r21,
         "users"."dealership_id"                                                                                       AS t0_r22,
         "users"."jobs_count"                                                                                          AS t0_r23,
         "users"."videos_count"                                                                                        AS t0_r24,
         "users"."is_admin"                                                                                            AS t0_r25,
         "users"."created_at"                                                                                          AS t0_r26,
         "users"."updated_at"                                                                                          AS t0_r27,
         "users"."username"                                                                                            AS t0_r28
FROM     "users" 
WHERE    "users"."role" = 'service_technician' 
AND      (( 
                           "users"."email" ilike '%rodrigo%' 
                  OR       "users"."name" ilike '%rodrigo%' 
                  OR       "users"."phone" ilike '%rodrigo%' 
                  OR       "users"."role" ilike '%rodrigo%')) 
ORDER BY "users"."id" DESC limit 1

with_sums() is a method which adds the custom functions to query and it works more or less that (it's kind of long and complex so here is just an example of how it works):

def self.with_stats
  self.select('custom_function(*) AS total_ro_value, custom_function(*) AS total_final_ro_value, ...')
end

[mrkamel]

I don't fully understand. You're using User.with_sums.search('rodrigo').total_ro_value, but User.with_sums.search('rodrigo') returns an ActiveRecord::Relation Object. Maybe your pseudo-code of with_stats/with_sums is incomplete. However, what about using #first , such that User.with_sums.search('rodrigo').first.total_ro_value ?

Otherwise, please tell me what the rails console tells you about User.with_sums.class VS User.with_sums.search('rodrigo').class

[mbajur]

Oh crap, sorry, you're right, there was a typo in the first lines of provided code samples, they should be User.with_sums.last.total_ro_value and User.with_sums.search('rodrigo').last.total_ro_value. Previous comment fixed.

[mrkamel]

What happens when you run the sql generated for User.with_sums.search('rodrigo').last.total_ro_value from the postgres console? Does it return the desired values for total_ro_value, etc? Maybe paste the postgres result as well.

[mbajur]

Yes, running generated query in pgadmin returns desired columns. i'm not
able to submit the results right now cause i'm out of home but they look
as expected

[mrkamel]

Ok, the problem is SearchCop calls eager_load even when no assocations are referenced, such that eager_load([]) is called. I'll push a patch. The patch should fix your issue as long as you don't reference any associations. If, however, in the future, you reference any associations, you'll have to do the joining yourself via a scope block, as initially stated. Thanks.

[mbajur]

Great to hear it's tracked down. Thank you for your help and time mrkamel! I'm looking forward to the patch.

[mrkamel]

Could you confirm, that this fixes your issue, before i bump a new gem version?
To install it, update your Gemfile:

gem "search_cop", :git => "https://github.com/mrkamel/search_cop.git"

$ bundle update search_cop

[mbajur]

Yes, now it works. Thank you so much!