1

This has been tremendously frustrating. I'm trying to get a has_many through working, and I think I'm just too close to this to see something super obvious. Each step works correctly, and the SQL that Rails is generating works, but together in the console it's not.

The one weird thing about this whole setup is that there are a couple of tables in a salesforce schema, and the tablename and primary key aren't standard. Here's the basic structure:

class Contact
  self.table_name =  'salesforce.contact'
  self.primary_key = 'sfid'

  has_many :content_accesses
  has_many :inventories, through: :content_accesses # I've tried inventory and inventorys, just to ensure it's not Rails magic
end


class ContentAccess
  belongs_to :inventory
  belongs_to :contact
end


class Inventory
  self.table_name =  'salesforce.inventory__c'
  self.primary_key = 'sfid'

  has_many :content_accesses, foreign_key: 'inventory_id'
end

Works:

c = Contact.first
c.content_accesses # works, gives the related items

c.content_accesses.first.inventory # works, gives the related Inventory item

Error:

c.inventories # Gives:

# ActiveRecord::StatementInvalid (PG::UndefinedTable: ERROR:  relation "content_accesses" does not exist)
# LINE 1: ..._c".* FROM "salesforce"."inventory__c" INNER JOIN "content_a...
#                                                          ^
# : SELECT  "salesforce"."inventory__c".* FROM "salesforce"."inventory__c" INNER JOIN "content_accesses" ON "salesforce"."inventory__c"."sfid" = "content_accesses"."inventory_id" WHERE "content_accesses"."contact_id" = $1 LIMIT $2

When I run that query through Postico, though, it works fine.

Edited to add:

  • I moved content_accesses into the salesforce schema, and set self.table_name on the model correctly, but the problem still happens. As such, I don't think this is related to being cross-schema.
  • That only makes this problem weirder to me. :(

DDL for the tables:

CREATE TABLE salesforce.inventory__c (
    createddate timestamp without time zone,
    isdeleted boolean,
    name character varying(80),
    systemmodstamp timestamp without time zone,
    inventory_unique_name__c character varying(255),
    sfid character varying(18),
    id integer DEFAULT nextval('salesforce.inventory__c_id_seq'::regclass) PRIMARY KEY,
    _hc_lastop character varying(32),
    _hc_err text
);

CREATE UNIQUE INDEX inventory__c_pkey ON salesforce.inventory__c(id int4_ops);
CREATE INDEX hc_idx_inventory__c_systemmodstamp ON salesforce.inventory__c(systemmodstamp timestamp_ops);
CREATE UNIQUE INDEX hcu_idx_inventory__c_sfid ON salesforce.inventory__c(sfid text_ops);


CREATE TABLE salesforce.contact (
    lastname character varying(80),
    mailingpostalcode character varying(20),
    accountid character varying(18),
    assistantname character varying(40),
    name character varying(121),
    mobilephone character varying(40),
    birthdate date,
    phone character varying(40),
    mailingstreet character varying(255),
    isdeleted boolean,
    assistantphone character varying(40),
    systemmodstamp timestamp without time zone,
    mailingstatecode character varying(10),
    createddate timestamp without time zone,
    mailingcity character varying(40),
    salutation character varying(40),
    title character varying(128),
    mailingcountrycode character varying(10),
    firstname character varying(40),
    email character varying(80),
    sfid character varying(18),
    id integer DEFAULT nextval('salesforce.contact_id_seq'::regclass) PRIMARY KEY,
    _hc_lastop character varying(32),
    _hc_err text
);

CREATE UNIQUE INDEX contact_pkey ON salesforce.contact(id int4_ops);
CREATE INDEX hc_idx_contact_systemmodstamp ON salesforce.contact(systemmodstamp timestamp_ops);
CREATE UNIQUE INDEX hcu_idx_contact_sfid ON salesforce.contact(sfid text_ops);

CREATE TABLE content_accesses (
    id BIGSERIAL PRIMARY KEY,
    inventory_id character varying(20),
    contact_id character varying(20),
    created_at timestamp without time zone NOT NULL,
    updated_at timestamp without time zone NOT NULL
);

CREATE UNIQUE INDEX content_accesses_pkey ON content_accesses(id int8_ops);

Edit 2: As part of debugging, I've tried running the generated query in the console:

  • If I run the generated query using ActiveRecord::Base.connection.execute the query works.
  • If I run it through Contact.connection.execute it gives the same error.

It feels like Rails is not figuring something out, but I can't figure out where or why or what.

Edit 3: As requested, the framework trace:

activerecord (5.2.0) lib/active_record/connection_adapters/postgresql_adapter.rb:669:in `prepare'
activerecord (5.2.0) lib/active_record/connection_adapters/postgresql_adapter.rb:669:in `block in prepare_statement'
/Users/timsullivan/.rvm/rubies/ruby-2.5.1/lib/ruby/2.5.0/monitor.rb:226:in `mon_synchronize'
activerecord (5.2.0) lib/active_record/connection_adapters/postgresql_adapter.rb:664:in `prepare_statement'
activerecord (5.2.0) lib/active_record/connection_adapters/postgresql_adapter.rb:609:in `exec_cache'
activerecord (5.2.0) lib/active_record/connection_adapters/postgresql_adapter.rb:592:in `execute_and_clear'
activerecord (5.2.0) lib/active_record/connection_adapters/postgresql/database_statements.rb:81:in `exec_query'
activerecord (5.2.0) lib/active_record/connection_adapters/abstract/database_statements.rb:469:in `select_prepared'
activerecord (5.2.0) lib/active_record/connection_adapters/abstract/database_statements.rb:55:in `select_all'
activerecord (5.2.0) lib/active_record/connection_adapters/abstract/query_cache.rb:101:in `select_all'
activerecord (5.2.0) lib/active_record/querying.rb:41:in `find_by_sql'
activerecord (5.2.0) lib/active_record/relation.rb:554:in `block in exec_queries'
activerecord (5.2.0) lib/active_record/relation.rb:578:in `skip_query_cache_if_necessary'
activerecord (5.2.0) lib/active_record/relation.rb:542:in `exec_queries'
activerecord (5.2.0) lib/active_record/association_relation.rb:34:in `exec_queries'
activerecord (5.2.0) lib/active_record/relation.rb:414:in `load'
activerecord (5.2.0) lib/active_record/relation.rb:200:in `records'
activerecord (5.2.0) lib/active_record/relation.rb:195:in `to_ary'
activerecord (5.2.0) lib/active_record/relation/finder_methods.rb:530:in `find_nth_with_limit'
activerecord (5.2.0) lib/active_record/associations/collection_proxy.rb:1136:in `find_nth_with_limit'
activerecord (5.2.0) lib/active_record/relation/finder_methods.rb:515:in `find_nth'
activerecord (5.2.0) lib/active_record/relation/finder_methods.rb:125:in `first'
actionview (5.2.0) lib/action_view/template.rb:159:in `block in render'
activesupport (5.2.0) lib/active_support/notifications.rb:170:in `instrument'
actionview (5.2.0) lib/action_view/template.rb:354:in `instrument_render_template'
actionview (5.2.0) lib/action_view/template.rb:157:in `render'
actionview (5.2.0) lib/action_view/renderer/template_renderer.rb:54:in `block (2 levels) in render_template'
actionview (5.2.0) lib/action_view/renderer/abstract_renderer.rb:44:in `block in instrument'
activesupport (5.2.0) lib/active_support/notifications.rb:168:in `block in instrument'
activesupport (5.2.0) lib/active_support/notifications/instrumenter.rb:23:in `instrument'
activesupport (5.2.0) lib/active_support/notifications.rb:168:in `instrument'
actionview (5.2.0) lib/action_view/renderer/abstract_renderer.rb:43:in `instrument'
actionview (5.2.0) lib/action_view/renderer/template_renderer.rb:53:in `block in render_template'
actionview (5.2.0) lib/action_view/renderer/template_renderer.rb:61:in `render_with_layout'
actionview (5.2.0) lib/action_view/renderer/template_renderer.rb:52:in `render_template'
actionview (5.2.0) lib/action_view/renderer/template_renderer.rb:16:in `render'
actionview (5.2.0) lib/action_view/renderer/renderer.rb:44:in `render_template'
actionview (5.2.0) lib/action_view/renderer/renderer.rb:25:in `render'
actionview (5.2.0) lib/action_view/rendering.rb:103:in `_render_template'
actionpack (5.2.0) lib/action_controller/metal/streaming.rb:219:in `_render_template'
actionview (5.2.0) lib/action_view/rendering.rb:84:in `render_to_body'
actionpack (5.2.0) lib/action_controller/metal/rendering.rb:52:in `render_to_body'
actionpack (5.2.0) lib/action_controller/metal/renderers.rb:142:in `render_to_body'
actionpack (5.2.0) lib/abstract_controller/rendering.rb:25:in `render'
actionpack (5.2.0) lib/action_controller/metal/rendering.rb:36:in `render'
actionpack (5.2.0) lib/action_controller/metal/instrumentation.rb:46:in `block (2 levels) in render'
activesupport (5.2.0) lib/active_support/core_ext/benchmark.rb:14:in `block in ms'
/Users/timsullivan/.rvm/rubies/ruby-2.5.1/lib/ruby/2.5.0/benchmark.rb:308:in `realtime'
activesupport (5.2.0) lib/active_support/core_ext/benchmark.rb:14:in `ms'
actionpack (5.2.0) lib/action_controller/metal/instrumentation.rb:46:in `block in render'
actionpack (5.2.0) lib/action_controller/metal/instrumentation.rb:87:in `cleanup_view_runtime'
activerecord (5.2.0) lib/active_record/railties/controller_runtime.rb:31:in `cleanup_view_runtime'
actionpack (5.2.0) lib/action_controller/metal/instrumentation.rb:45:in `render'
actionpack (5.2.0) lib/action_controller/metal/implicit_render.rb:35:in `default_render'
actionpack (5.2.0) lib/action_controller/metal/basic_implicit_render.rb:6:in `block in send_action'
actionpack (5.2.0) lib/action_controller/metal/basic_implicit_render.rb:6:in `tap'
actionpack (5.2.0) lib/action_controller/metal/basic_implicit_render.rb:6:in `send_action'
actionpack (5.2.0) lib/abstract_controller/base.rb:194:in `process_action'
actionpack (5.2.0) lib/action_controller/metal/rendering.rb:30:in `process_action'
actionpack (5.2.0) lib/abstract_controller/callbacks.rb:42:in `block in process_action'
activesupport (5.2.0) lib/active_support/callbacks.rb:132:in `run_callbacks'
actionpack (5.2.0) lib/abstract_controller/callbacks.rb:41:in `process_action'
actionpack (5.2.0) lib/action_controller/metal/rescue.rb:22:in `process_action'
actionpack (5.2.0) lib/action_controller/metal/instrumentation.rb:34:in `block in process_action'
activesupport (5.2.0) lib/active_support/notifications.rb:168:in `block in instrument'
activesupport (5.2.0) lib/active_support/notifications/instrumenter.rb:23:in `instrument'
activesupport (5.2.0) lib/active_support/notifications.rb:168:in `instrument'
actionpack (5.2.0) lib/action_controller/metal/instrumentation.rb:32:in `process_action'
actionpack (5.2.0) lib/action_controller/metal/params_wrapper.rb:256:in `process_action'
activerecord (5.2.0) lib/active_record/railties/controller_runtime.rb:24:in `process_action'
actionpack (5.2.0) lib/abstract_controller/base.rb:134:in `process'
actionview (5.2.0) lib/action_view/rendering.rb:32:in `process'
actionpack (5.2.0) lib/action_controller/metal.rb:191:in `dispatch'
actionpack (5.2.0) lib/action_controller/metal.rb:252:in `dispatch'
actionpack (5.2.0) lib/action_dispatch/routing/route_set.rb:52:in `dispatch'
actionpack (5.2.0) lib/action_dispatch/routing/route_set.rb:34:in `serve'
actionpack (5.2.0) lib/action_dispatch/journey/router.rb:52:in `block in serve'
actionpack (5.2.0) lib/action_dispatch/journey/router.rb:35:in `each'
actionpack (5.2.0) lib/action_dispatch/journey/router.rb:35:in `serve'
actionpack (5.2.0) lib/action_dispatch/routing/route_set.rb:840:in `call'
warden (1.2.7) lib/warden/manager.rb:36:in `block in call'
warden (1.2.7) lib/warden/manager.rb:35:in `catch'
warden (1.2.7) lib/warden/manager.rb:35:in `call'
rack (2.0.5) lib/rack/tempfile_reaper.rb:15:in `call'
rack (2.0.5) lib/rack/etag.rb:25:in `call'
rack (2.0.5) lib/rack/conditional_get.rb:25:in `call'
rack (2.0.5) lib/rack/head.rb:12:in `call'
actionpack (5.2.0) lib/action_dispatch/http/content_security_policy.rb:18:in `call'
rack (2.0.5) lib/rack/session/abstract/id.rb:232:in `context'
rack (2.0.5) lib/rack/session/abstract/id.rb:226:in `call'
actionpack (5.2.0) lib/action_dispatch/middleware/cookies.rb:670:in `call'
activerecord (5.2.0) lib/active_record/migration.rb:559:in `call'
actionpack (5.2.0) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
activesupport (5.2.0) lib/active_support/callbacks.rb:98:in `run_callbacks'
actionpack (5.2.0) lib/action_dispatch/middleware/callbacks.rb:26:in `call'
actionpack (5.2.0) lib/action_dispatch/middleware/executor.rb:14:in `call'
airbrake (7.2.1) lib/airbrake/rack/middleware.rb:52:in `call'
actionpack (5.2.0) lib/action_dispatch/middleware/debug_exceptions.rb:61:in `call'
web-console (3.6.1) lib/web_console/middleware.rb:135:in `call_app'
web-console (3.6.1) lib/web_console/middleware.rb:30:in `block in call'
web-console (3.6.1) lib/web_console/middleware.rb:20:in `catch'
web-console (3.6.1) lib/web_console/middleware.rb:20:in `call'
actionpack (5.2.0) lib/action_dispatch/middleware/show_exceptions.rb:33:in `call'
railties (5.2.0) lib/rails/rack/logger.rb:38:in `call_app'
railties (5.2.0) lib/rails/rack/logger.rb:26:in `block in call'
activesupport (5.2.0) lib/active_support/tagged_logging.rb:71:in `block in tagged'
activesupport (5.2.0) lib/active_support/tagged_logging.rb:28:in `tagged'
activesupport (5.2.0) lib/active_support/tagged_logging.rb:71:in `tagged'
railties (5.2.0) lib/rails/rack/logger.rb:26:in `call'
sprockets-rails (3.2.1) lib/sprockets/rails/quiet_assets.rb:13:in `call'
actionpack (5.2.0) lib/action_dispatch/middleware/remote_ip.rb:81:in `call'
actionpack (5.2.0) lib/action_dispatch/middleware/request_id.rb:27:in `call'
rack (2.0.5) lib/rack/method_override.rb:22:in `call'
rack (2.0.5) lib/rack/runtime.rb:22:in `call'
activesupport (5.2.0) lib/active_support/cache/strategy/local_cache_middleware.rb:29:in `call'
actionpack (5.2.0) lib/action_dispatch/middleware/executor.rb:14:in `call'
actionpack (5.2.0) lib/action_dispatch/middleware/static.rb:127:in `call'
rack (2.0.5) lib/rack/sendfile.rb:111:in `call'
webpacker (3.4.3) lib/webpacker/dev_server_proxy.rb:18:in `perform_request'
rack-proxy (0.6.4) lib/rack/proxy.rb:57:in `call'
railties (5.2.0) lib/rails/engine.rb:524:in `call'
puma (3.11.4) lib/puma/configuration.rb:225:in `call'
puma (3.11.4) lib/puma/server.rb:632:in `handle_request'
puma (3.11.4) lib/puma/server.rb:446:in `process_client'
puma (3.11.4) lib/puma/server.rb:306:in `block in run'
puma (3.11.4) lib/puma/thread_pool.rb:120:in `block in spawn_thread'
Tim Sullivan
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  • In Rails `inventorys` should be `inventories`. Can you do `spring stop` and restart the console and try again. – Arup Rakshit Aug 13 '18 at 19:44
  • Yeah, I tried all variations of that (I mentioned it in the comment beside the poorly named item). I did try it again just now, as I'd not tried `spring stop`. However, the problem remains. – Tim Sullivan Aug 13 '18 at 19:47
  • I updated the question to make it more correct, so it won't confuse anyone else. :D – Tim Sullivan Aug 13 '18 at 19:48
  • so you have 2 schemas right? – Arup Rakshit Aug 13 '18 at 19:55
  • There is one "schemaless" (maybe "public"?) set of tables, the default ones that were created, and a second "salesforce" schema, which contains tables that were imported from Salesforce. – Tim Sullivan Aug 13 '18 at 20:20
  • I think the problem arises due to [multiple schemas](https://stackoverflow.com/questions/8427865/rails-postgresql-multiple-schemas-and-the-same-table-name). Can you check the answer and see if it works for you? – Arup Rakshit Aug 13 '18 at 20:28
  • Setting schema_search_path did not help. The table names are all qualified and include the schema, and it's working everywhere else. – Tim Sullivan Aug 13 '18 at 20:42
  • Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/177974/discussion-between-arup-rakshit-and-tim-sullivan). – Arup Rakshit Aug 13 '18 at 20:49
  • @TimSullivan can you add a list of all fields of those tables, it looks like you didn't specify primary_key on it – itsnikolay Aug 20 '18 at 13:34
  • The `content_accesses` table is using Rails defaults; the primary key is 'id'. However, I did specify `self.primary_key = 'id'` and it still doesn't work. – Tim Sullivan Aug 20 '18 at 15:08
  • I've added the table definitions, @itsnikolay. Let me know if that helps. – Tim Sullivan Aug 20 '18 at 15:21
  • Have you tried setting a fully-qualified `table_name` for your `ContactAccess` model? Ie. add `self.table_name = 'public.contact_accesses'` at the top of your `class ContactAccess` definition? (assuming `contact_accesses` lives in `public` - which is where the schemaless version in the generated SQL should be finding it) – Timshel Aug 22 '18 at 02:37
  • I have! It doesn't help, unfortunately. :( – Tim Sullivan Aug 22 '18 at 13:55

2 Answers2

1

Since you say, the generated SQL works when you directly invoke it the problem root lies somewhere in the process of mapping the returned data back to Objects. Even though your setup looks fine, it seems pretty non standard, so I would try giving rails more hints on how the associations belong together.

To start with you should set a source for your through relation (docs): 

has_many :inventories, through: :content_accesses, source: :inventory

If that still does not give rails the right clue, you can try setting inverse_of, foreign_key, primary_key and even class_name on the other belongs_to and has_many associations, to give rails the required hints. It is hard to tell what could possibly help, but in non standard setups you sometimes experience certain problems with automatically inferred names.

smallbutton
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  • So, I tried all this, setting everything: `has_many :inventories, through: :content_accesses, class_name: 'Inventory', foreign_key: 'inventory_id', source: :inventory` and similar on the other side, including `inverse_of`, and still giving errors. If I run the generated query using `ActiveRecord::Base.connection.execute` the query works, if I run it through `Contact.connection.execute` it gives the same error. It feels like Rails is not figuring something out, but I can't figure out where or why or what. – Tim Sullivan Aug 22 '18 at 13:39
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    To me, it seems like a bug in rails then. Can you provide a stacktrace or the exception (at least the framework trace)? – smallbutton Aug 22 '18 at 16:47
  • I'm thinking the same thing. I added a framework trace to the question. – Tim Sullivan Aug 22 '18 at 17:21
0

Embarrassingly, this was a configuration problem. The contents of the salesforce schema were being loaded from the server, and not from my local database. It's the one thing I didn't think to doublecheck, and the contents of the local salesforce schema worked because I'd restored a backup from the server.

Setting the proper HEROKUCONNECT_URL to my local Postgres server fixed the issue, though I would work around it by moving ContentAccess's table into Salesforce and then creating a fresh copy of the database from the server for local use.

If you feel like laughing at my foolishness further, you can check out the followup question I had that was a different but similar example of PBKAC.

Tim Sullivan
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