Rails中的复杂Postgres查询

Question

当前正在查询具有参数premium_amount_lower_range, premium_amount_upper_range, application_date_lower_range, application_date_upper_range, insurance_type_id过滤器

@filtered_quotes = current_user.insurance_subscribers.includes(:insurance_types).includes(:insurance_subscribers_types, :insurance_subscribers_types_carriers).
                   premium_amount(params[:dashboard][:premium_amount_lower_range], params[:dashboard][:premium_amount_upper_range]).
                   duration(params[:dashboard][:application_date_lower_range], params[:dashboard][:application_date_upper_range]).
                   insurance_type(params[:dashboard][:insurance_type_id])

但是现在还需要根据其状态进行过滤。 有问题。 我在insurance_subscribers和insurance_subscribers_types_carriers表中有“状态”列，这两个列都是枚举。

我试图添加where子句，例如

@filtered_quotes = current_user.insurance_subscribers.includes(:insurance_types).includes(:insurance_subscribers_types, :insurance_subscribers_types_carriers).
               where("insurance_subscribers_types_carriers.status = 1")
#              ...

这给了我错误PG::UndefinedTable: ERROR: missing FROM-clause entry for table "insurance_subscribers_types_carriers"

但是当我尝试去喜欢

@filtered_quotes = current_user.insurance_subscribers.includes(:insurance_types).includes(:insurance_subscribers_types, :insurance_subscribers_types_carriers).
           where(status: 1)
#          .... 

这会将where子句放在insurance_subscribers上。

试图在上述查询中添加一个简单的where子句WHERE insurance_subscribers_types_carriers.status = 1 ，但此查询有很多麻烦。

协会

insurance_subscriber.rb

has_many :insurance_subscribers_types, dependent: :destroy
has_many :insurance_types, through: :insurance_subscribers_types
has_many :insurance_subscribers_types_carriers, through: :insurance_subscribers_types

insurance_types.rb

has_many :insurance_subscribers, through: :insurance_subscribers_types
has_many :insurance_subscribers_types
has_many :insurance_subscribers_types_carriers

insurance_subscriber_type.rb

belongs_to :insurance_subscriber
belongs_to :insurance_type
has_many :carriers, through: :insurance_subscribers_types_carriers
has_many :insurance_subscribers_types_carriers, dependent: :destroy

insurance_subscribers_types_carrier.rb

belongs_to :carrier
belongs_to :insurance_subscribers_type

Answer 1

如果要跨关联模型添加queries ，则首先需要将它们加入。 由于您具有has_may :through关联，因此可以按以下方式完成所需的操作：

InsuranceSubscriber.joins(insurance_subscriber_types: :insurance_subscribers_types_carriers)
.includes(:insurance_types, :insurance_subscribers_types, :insurance_subscribers_types_carriers)
.where("insurance_subscribers_types_carriers.status = ?", 1)

如您所见，即使您具有has_many :through ，也可以加入并引用您的关联，如下所示joins(.joins(insurance_subscriber_types: :insurance_subscribers_types_carriers) 。

您将获得sql的输出，如下所示：

InsuranceSubscriber Load (3.3ms)  SELECT "insurance_subscribers".* FROM 
"insurance_subscribers" INNER JOIN "insurance_subscriber_types" ON 
"insurance_subscriber_types"."insurance_subscriber_id" = 
"insurance_subscribers"."id" INNER JOIN "insurance_subscribers_types_carriers" ON 
"insurance_subscribers_types_carriers"."insurance_subscriber_type_id" = 
"insurance_subscriber_types"."id" WHERE (insurance_subscribers_types_carriers.status = 1)

我使用模型结构复制并测试了您的问题，如下所示：

PS：我对您的型号名称做了一些小的更改，因此请小心。 他们是如此简化尝试。

insurance_subscriber.rb

# == Schema Information
#
# Table name: insurance_subscribers
#
#  id         :integer          not null, primary key
#  name       :string
#  status     :integer          default("0")
#  created_at :datetime         not null
#  updated_at :datetime         not null
#

class InsuranceSubscriber < ActiveRecord::Base
  has_many :insurance_subscriber_types, dependent: :destroy
  has_many :insurance_types, through: :insurance_subscriber_types
  has_many :insurance_subscribers_types_carriers, through:     :insurance_subscriber_types

  enum status: {active: 0, passive: 1}
end

insurance_subscriber_types.rb

# == Schema Information
#
# Table name: insurance_subscriber_types
#
#  id                      :integer          not null, primary key
#  name                    :string
#  insurance_subscriber_id :integer
#  insurance_type_id       :integer
#  created_at              :datetime         not null
#  updated_at              :datetime         not null
#

class InsuranceSubscriberType < ActiveRecord::Base
  belongs_to :insurance_subscriber
  belongs_to :insurance_type

  has_many :insurance_subscribers_types_carriers, dependent: :destroy
  has_many :carriers, through: :insurance_subscribers_types_carriers
end

insurance_subscribers_types_carriers.rb

# == Schema Information
#
# Table name: insurance_subscribers_types_carriers
#
#  id                           :integer          not null, primary key
#  carrier_id                   :integer
#  insurance_subscriber_type_id :integer
#  status                       :integer          default("0")
#  created_at                   :datetime         not null
#  updated_at                   :datetime         not null
#

class InsuranceSubscribersTypesCarrier < ActiveRecord::Base
  belongs_to :carrier
  belongs_to :insurance_subscriber_type

  enum status: {active: 0, passive: 1}
end

insurance_types.rb

# == Schema Information
#
# Table name: insurance_types
#
#  id         :integer          not null, primary key
#  name       :string
#  created_at :datetime         not null
#  updated_at :datetime         not null
#

class InsuranceType < ActiveRecord::Base
  has_many :insurance_subscribers_types_carriers
  has_many :insurance_subscribers_types_carriers
  has_many :insurance_subscribers, through: :insurance_subscribers_types
end

Answer 2

如果要在查询中使用包含的关联（insurance_subscribers_types_carriers），则必须添加“引用”，否则insurance_subscribers_types_carriers将与主查询分开加载：

InsuranceSubscriber.includes(:insurance_subscribers_types_carriers)
               .where("insurance_subscribers_types_carriers.status = ?", 1)
               .references(:insurance_subscribers_types_carriers)