rails中的复杂postgres查询

Question

当前具有参数premium_amount_lower_range, premium_amount_upper_range, application_date_lower_range, application_date_upper_range, insurance_type_id的筛选器的查询

@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])

但现在也需要根据自己的状态进行过滤。有问题。在insurance_subscribers和insurance_subscribers_types_carriers表中有status列，这两个列都是enum。

我试着添加where子句

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

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

但当我试着做的时候

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

这将把where子句放在insurance_subscribers上。

试图在上面的查询中添加一个简单的where子句WHERE insurance_subscribers_types_carriers.status = 1，但是这个查询有很多问题。

联想

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，首先需要加入它们。由于您有has_may :through关联，所以您可以按以下方式实现您的需要：

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)

正如您所看到的，您可以加入和引用您的关联，即使您有has_many :through关联，如下所示joins(.joins(insurance_subscriber_types: :insurance_subscribers_types_carriers)。

您将得到如下的sql输出：

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)

我用模型结构复制并测试了您的问题，如下所示：

PS:我对您的模型名做了一些小改动，所以要小心。它们令人困惑，试图简化它们。

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)