ruby-on-rails - Rails ActiveRecord::StatementInvalid: PG::Error: ERROR: 缺少表的 FROM 子句条目

Question

我有一个复杂的 ActiveRecord 查询，我正在根据用户的选择构建具有不同范围的查询。我正在使用 2 个 gem ，这似乎是有问题的，但我找不到谁是两者之间的罪魁祸首:Texticle(用于 Postgresql 完整搜索)(2.0.3)Squeel(用于 Active Record 查询中的 ruby​​ 语法)squeel (0.9.5)Arel 或 Active Record 本身

这是我的类定义:

class Event < ActiveRecord::Base
  belongs_to :entity, :class_name => "Entity", :foreign_key => :entity_id
  belongs_to :place, :class_name => "Entity", :foreign_key => :place_id

class Entity < ActiveRecord::Base
  has_many :events, :foreign_key => 'entity_id'
  has_many :events, :foreign_key => 'place_id'

最后，我的问题:

Event.joins{entity.outer}.joins{place.outer}.includes(:place).includes(:entity).textsearch('anystring'.downcase)

*这是一个 ActiveRecord::Relation 对象，当用 to_a 调用它时会崩溃

这给了我以下错误:

ActiveRecord::StatementInvalid: PG::Error: ERROR:  missing FROM-clause entry for table "entities_events"
LINE 1: ... AS t1_r30, "entities"."metro_area_id" AS t1_r31, "entities_...
                                                             ^
: SELECT "events"."id" AS t0_r0, "events"."name" AS t0_r1, "events"."start_at" AS t0_r2, "events"."end_at" AS t0_r3, "events"."created_at" AS t0_r4, "events"."updated_at" AS t0_r5, "events"."entity_id" AS t0_r6, "events"."calendar_id" AS t0_r7, "events"."location" AS t0_r8, "events"."facebook_id" AS t0_r9, "events"."updated_time" AS t0_r10, "events"."privacy" AS t0_r11, "events"."venue_id" AS t0_r12, "events"."description" AS t0_r13, "events"."venue_city" AS t0_r14, "events"."venue_country" AS t0_r15, "events"."venue_state" AS t0_r16, "events"."venue_longitude" AS t0_r17, "events"."venue_latitude" AS t0_r18, "events"."yahoo_city" AS t0_r19, "events"."yahoo_country" AS t0_r20, "events"."yahoo_state" AS t0_r21, "events"."yahoo_updated_at" AS t0_r22, "events"."fb_updated_at" AS t0_r23, "events"."source_id" AS t0_r24, "events"."source_type" AS t0_r25, "events"."source_url" AS t0_r26, "events"."status" AS t0_r27, "events"."category" AS t0_r28, "events"."place_id" AS t0_r29, "events"."metro_area_id" AS t0_r30, "entities"."id" AS t1_r0, "entities"."image_url" AS t1_r1, "entities"."created_at" AS t1_r2, "entities"."updated_at" AS t1_r3, "entities"."name" AS t1_r4, "entities"."facebook_id" AS t1_r5, "entities"."link" AS t1_r6, "entities"."website" AS t1_r7, "entities"."company_overview" AS t1_r8, "entities"."mission" AS t1_r9, "entities"."category" AS t1_r10, "entities"."picture" AS t1_r11, "entities"."city" AS t1_r12, "entities"."zip" AS t1_r13, "entities"."country" AS t1_r14, "entities"."street" AS t1_r15, "entities"."state" AS t1_r16, "entities"."events_updated_at" AS t1_r17, "entities"."fblikes_updated_at" AS t1_r18, "entities"."fb_updated_at" AS t1_r19, "entities"."source_url" AS t1_r20, "entities"."source_type" AS t1_r21, "entities"."source_id" AS t1_r22, "entities"."place" AS t1_r23, "entities"."latitude" AS t1_r24, "entities"."longitude" AS t1_r25, "entities"."yahoo_city" AS t1_r26, "entities"."yahoo_state" AS t1_r27, "entities"."yahoo_country" AS t1_r28, "entities"."yahoo_updated_at" AS t1_r29, "entities"."fetched_elements_at" AS t1_r30, "entities"."metro_area_id" AS t1_r31, "entities_events"."id" AS t2_r0, "entities_events"."image_url" AS t2_r1, "entities_events"."created_at" AS t2_r2, "entities_events"."updated_at" AS t2_r3, "entities_events"."name" AS t2_r4, "entities_events"."facebook_id" AS t2_r5, "entities_events"."link" AS t2_r6, "entities_events"."website" AS t2_r7, "entities_events"."company_overview" AS t2_r8, "entities_events"."mission" AS t2_r9, "entities_events"."category" AS t2_r10, "entities_events"."picture" AS t2_r11, "entities_events"."city" AS t2_r12, "entities_events"."zip" AS t2_r13, "entities_events"."country" AS t2_r14, "entities_events"."street" AS t2_r15, "entities_events"."state" AS t2_r16, "entities_events"."events_updated_at" AS t2_r17, "entities_events"."fblikes_updated_at" AS t2_r18, "entities_events"."fb_updated_at" AS t2_r19, "entities_events"."source_url" AS t2_r20, "entities_events"."source_type" AS t2_r21, "entities_events"."source_id" AS t2_r22, "entities_events"."place" AS t2_r23, "entities_events"."latitude" AS t2_r24, "entities_events"."longitude" AS t2_r25, "entities_events"."yahoo_city" AS t2_r26, "entities_events"."yahoo_state" AS t2_r27, "entities_events"."yahoo_country" AS t2_r28, "entities_events"."yahoo_updated_at" AS t2_r29, "entities_events"."fetched_elements_at" AS t2_r30, "entities_events"."metro_area_id" AS t2_r31 FROM "events" LEFT OUTER JOIN "entities" ON "entities"."id" = "events"."entity_id" LEFT OUTER JOIN "entities" "places_events" ON "places_events"."id" = "events"."place_id" WHERE (to_tsvector('english', "events"."name"::text) @@ to_tsquery('english', 'canadiens'::text))  ORDER BY "rank0.11630770538778923" DESC
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.2.1/lib/active_record/connection_adapters/postgresql_adapter.rb:1106:in `async_exec'
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.2.1/lib/active_record/connection_adapters/postgresql_adapter.rb:1106:in `exec_no_cache'
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.2.1/lib/active_record/connection_adapters/postgresql_adapter.rb:650:in `block in exec_query'
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.2.1/lib/active_record/connection_adapters/abstract_adapter.rb:280:in `block in log'
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/activesupport-3.2.1/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.2.1/lib/active_record/connection_adapters/abstract_adapter.rb:275:in `log'
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.2.1/lib/active_record/connection_adapters/postgresql_adapter.rb:649:in `exec_query'
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.2.1/lib/active_record/connection_adapters/postgresql_adapter.rb:1201:in `select'
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.2.1/lib/active_record/connection_adapters/abstract/database_statements.rb:16:in `select_all'
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.2.1/lib/active_record/connection_adapters/abstract/query_cache.rb:63:in `select_all'
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.2.1/lib/active_record/relation/finder_methods.rb:211:in `find_with_associations'
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.2.1/lib/active_record/relation.rb:170:in `exec_queries'
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.2.1/lib/active_record/relation.rb:159:in `block in to_a'
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.2.1/lib/active_record/explain.rb:40:in `logging_query_plan'
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.2.1/lib/active_record/relation.rb:158:in `to_a'
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-3.2.1/lib/active_record/relation.rb:495:in `inspect'
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/commands/console.rb:47:in `start'
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/commands/console.rb:8:in `start'
     from /Users/guillaumenm/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.2.1/lib/rails/commands.rb:41:in `<top (required)>'
     from ./script/rails:6:in `require'

If I call the to_sql method on the query, I get a working SQL statement like this :
 => "SELECT \"events\".*, ts_rank(to_tsvector('english', \"events\".\"name\"::text), to_tsquery('english', 'canadiens'::text)) AS \"rank0.7148935848557265\" FROM \"events\" LEFT OUTER JOIN \"entities\" ON \"entities\".\"id\" = \"events\".\"entity_id\" WHERE (to_tsvector('english', \"events\".\"name\"::text) @@ to_tsquery('english', 'canadiens'::text)) AND ((\"events\".\"start_at\" >= '2012-02-19T00:00:00+00:00' AND \"events\".\"start_at\" <= '2012-02-25T23:59:59+00:00')) ORDER BY \"rank0.7148935848557265\" DESC"

• Active Record 和 ARel 是否完全负责执行完整的 sql 语句？
• 为什么 to_sql 不会产生相同的结果？

• 有什么方法可以强制(不提供完整的 OUTER JOIN 语法)连接名称？

• 我如何确保捕获有问题的部分以填写正确的错误报告？我迷失在我的调试器中，试图找到哪段代码编写了不正确的连接语句 ||或具有无效连接关联名称的不正确 SELECT 子句。

谢谢

Answer 1

我刚刚遇到了同样的错误，这行代码:

SampleItem.joins(:campaign_market).where(campaign_market: {market_id: current_admin_user.market_id})

我的原因比上面的简单得多，joins(:campaign_market) 是正确的，因为它是一个 belongs_to/parent 记录，但是:

.where(campaign_market: {market_id: current_admin_user.market_id})

应该是:

.where(campaign_markets: {market_id: current_admin_user.market_id})

.where() 子句总是需要复数形式的表名，而不是关联名。