ActiveRecord::StatementInvalid, PG::UndefinedTable 错误，但生成的 SQL 有效答案

【问题标题】：ActiveRecord::StatementInvalid, PG::UndefinedTable error, but generated SQL worksActiveRecord::StatementInvalid, PG::UndefinedTable 错误，但生成的 SQL 有效
【发布时间】：2019-01-20 14:28:11
【问题描述】：

这非常令人沮丧。我正试图通过工作获得一个 has_many，我认为我离这个太近了，看不到一些非常明显的东西。每个步骤都能正常工作，Rails 生成的 SQL 也能正常工作，但在控制台中却不是。

整个设置的一个奇怪之处在于 Salesforce 架构中有几个表，并且表名和主键不是标准的。这是基本结构：

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

作品：

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

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

错误：

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

不过，当我通过Postico 运行该查询时，它运行良好。 ????

编辑添加：

我将 content_accesses 移到了 salesforce 架构中，并在模型上正确设置了 self.table_name，但问题仍然存在。因此，我认为这与跨模式无关。
这只会让我觉得这个问题更奇怪。 :(

表的 DDL：

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);

编辑 2： 作为调试的一部分，我尝试在控制台中运行生成的查询：

如果我使用ActiveRecord::Base.connection.execute 运行生成的查询，则查询有效。
如果我通过Contact.connection.execute 运行它，它会给出同样的错误。

感觉 Rails 并没有弄清楚什么，但我不知道在哪里、为什么或什么。

编辑 3： 根据要求，框架跟踪：

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'

【问题讨论】：

在 Rails 中 inventorys 应该是 inventories。可以spring stop 重启控制台再试一次吗？
是的，我尝试了所有变体（我在名称不佳的项目旁边的评论中提到了它）。我刚才确实又试了一次，因为我没有尝试过spring stop。但是，问题仍然存在。
我更新了问题以使其更正确，因此不会混淆其他人。 :D
所以你有 2 个模式对吗？
有一组“无模式”（可能是“公共”？）表，即创建的默认表，以及第二个“salesforce”模式，其中包含从 Salesforce 导入的表。

标签： ruby-on-rails postgresql

【解决方案1】：

正如你所说，当你直接调用生成的 SQL 时，它的问题根源在于将返回的数据映射回对象的过程中的某个地方。尽管您的设置看起来不错，但它似乎很不标准，所以我会尝试向 rails 提供更多关于关联如何归属的提示。

首先你应该为你的through关系(docs)设置一个source：

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

如果这仍然不能为 rails 提供正确的线索，您可以尝试在另一个 belongs_to 和 has_many 关联上设置 inverse_of、foreign_key、primary_key 甚至 class_name，以给 rails需要的提示。很难说有什么可能有帮助，但在非标准设置中，您有时会遇到自动推断名称的某些问题。

【讨论】：

所以，我尝试了所有这些，设置了所有内容：has_many :inventories, through: :content_accesses, class_name: 'Inventory', foreign_key: 'inventory_id', source: :inventory 和另一边的类似内容，包括inverse_of，但仍然报错。如果我使用ActiveRecord::Base.connection.execute 运行生成的查询，则查询有效，如果我通过Contact.connection.execute 运行它，则会给出相同的错误。感觉 Rails 没有弄清楚什么，但我不知道在哪里、为什么或什么。
对我来说，这似乎是 Rails 中的一个错误。您能否提供堆栈跟踪或异常（至少是框架跟踪）？
我也在想同样的事情。我在问题中添加了框架跟踪。

【解决方案2】：

令人尴尬的是，这是一个配置问题。 salesforce 模式的内容是从服务器加载的，而不是从我的本地数据库加载的。这是我没想过要仔细检查的一件事，并且本地 salesforce 模式的内容有效，因为我从服务器恢复了备份。

为我的本地 Postgres 服务器设置正确的 HEROKUCONNECT_URL 解决了这个问题，不过我会通过将 ContentAccess 的表移动到 Salesforce 中，然后从服务器创建数据库的新副本以供本地使用来解决这个问题。

如果你想进一步嘲笑我的愚蠢，你可以check out the followup question 我知道这是PBKAC 的一个不同但相似的例子。

【讨论】：