Question

我的Rails应用程序中有一个独立的问题模型，其中的问题是通过YAML加载的。我找到了正确的问题，并通过创建SaleQualifier（有一个question_id字段）将其加载到视图中，但我没有声明关联（例如SaleQualifier has_one问题），因为这会破坏网站的其他部分。

现在我想在我的应用程序中找到SaleQualifiers，具体取决于SaleQualifier和Question模型中的字段 - 我正在尝试编写正确的SQL查询，以便我可以检索记录。任何人都可以帮助我理解如何有效地编写这个，因为这是我第一次尝试编写自己的SQL命令。

我的架构：

create_table "questions", force: true do |t|
 t.text     "question_text"
 t.string   "answer_type"
 t.integer  "next_question_id_yes"
 t.integer  "next_question_id_no"
 t.datetime "created_at"
 t.datetime "updated_at"
 t.string   "sale_stage"
 t.boolean  "collectable",          default: false
end

  create_table "sale_qualifiers", force: true do |t|
   t.integer  "question_id"
   t.integer  "next_question_id",     default: 1
   t.datetime "created_at"
   t.datetime "updated_at"
   t.integer  "sales_opportunity_id"
   t.boolean  "has_answer",           default: false
   t.integer  "prior_question_id",    default: 1
   t.integer  "collection_id"
 end

我的问题.rb：

class Question < ActiveRecord::Base
 validates :next_question_id_yes, :question_text, :answer_type, presence: true

 File.open("#{Rails.root}/config/initializers/questions.yml", 'r') do |file|
   YAML::load(file).each do |record|
      Question.create(record) unless Question.exists?(record)
   end
 end
end

SaleQualifier.rb：

class SaleQualifier < ActiveRecord::Base
 has_one :answer, :inverse_of => :sale_qualifier, dependent: :destroy
 accepts_nested_attributes_for :answer
 belongs_to :sales_opportunity
 validates :sales_opportunity_id, presence: true
 validates_associated :answer
 after_save :update_sales_opp_question
end

一个示例问题：

- id: 1
 question_text: Why does this company need to buy your products or services?
 answer_type: Text Field
 next_question_id_yes: 2
 next_question_id_no: ~
 collectable: ~
 sale_stage: Prospecting

我想要实现的是找到属于sales_opportunity的所有SaleQualifiers，has_answer：'true'，并且问题sale_stage是Prospecting。

我尝试了什么：

SaleQualifier.find_by_sql("SELECT * FROM sale_qualifiers WHERE sales_opportunity_id = '83' has_answer = 'true' INNER JOIN questions ON questions.id = sale_qualifiers.question_id ORDER question.id desc")

导致以下错误：

SaleQualifier Load (15.8ms)  SELECT * FROM sale_qualifiers INECT * FROM sale_qualifiers WHERE sales_opportunity_id = '83' has_answer = 'true' INNER JOIN questions ON questions.id = sale_qualifiers.question_id ORDER question.id desc
PG::Error: ERROR:  syntax error at or near "*"
LINE 1: SELECT * FROM sale_qualifiers INECT * FROM sale_qualifiers W...

有人可以帮我理解如何写这个查询吗？

Answer 1

试

SaleQualifier.find_by_sql("SELECT sale_qualifiers.* FROM sale_qualifiers WHERE sales_opportunity_id = '83' has_answer = 'true' INNER JOIN questions ON questions.id = sale_qualifiers.question_id ORDER question.id desc")

如何在不声明关联的情况下在Rails中正确编写此SQL查询？

1 个答案: