Ruby on rails 默认情况下，PostgreSQL按另一个属性排序，然后按我定义的任何属性排序？

我有一个IndexQuery，在这里我丰富了一组用户，然后对其应用了不同的过滤器

class Users::IndexQuery
  def initialize(users)
    @users = users
  end

  def call
    @users.kept.created_desc
      .select(
        "users.*",
        "COALESCE(paid_invoices.paid_amount_cents,0) AS paid_amount_cents",
        "COALESCE(unpaid_invoices.unpaid_amount_cents,0) AS unpaid_amount_cents",
      )
      .joins(joins_paid_invoices, joins_unpaid_invoices, :subscription)
      .includes(:subscription)
  end

  private

  def joins_paid_invoices
    @joins_paid_invoices ||= <<-SQL
      LEFT OUTER JOIN (
        SELECT invoices.user_id as user_id,
               SUM(invoices.amount_cents) as paid_amount_cents
        FROM invoices
        WHERE invoices.status = 'paid'
        GROUP BY user_id
      )
      AS paid_invoices
      ON paid_invoices.user_id = users.id
    SQL
  end

  def joins_unpaid_invoices
    @joins_unpaid_invoices ||= <<-SQL
      LEFT OUTER JOIN (
        SELECT invoices.user_id AS user_id,
               SUM(invoices.amount_cents) as unpaid_amount_cents
        FROM invoices
        WHERE invoices.status = 'unpaid'
        GROUP BY user_id
      )
      AS unpaid_invoices
      ON unpaid_invoices.user_id = users.id
    SQL
  end
end

但是，在控制台中使用

.to_sql

在末尾运行查询会打印以下内容：

ORDER BY \"users\".\"id\" DESC, subscriptions.trial_end ASC"

无论是在控制器中还是在

索引查询中，我都没有指定它应该按
Users.id
排序。可能有什么问题？为什么默认情况下按该属性排序

编辑：我在IndexQuery中有一个
用户分组.id
。这可能是问题所在吗？
在Postgres 9.4+上，您可以大大简化这一点，从而为聚合函数的结果设置条件：

# see https://github.com/rubocop/ruby-style-guide#namespace-definition
module  Users
  class IndexQuery
    def initialize(users)
      @users = users
    end

    def call
      @users.kept.created_desc
        .joins(:invoices)
        .group(:id)
        .select(
          User.arel_table[:*],
          'SUM(invoices.amount_cents) FILTER (WHERE invoices.paid = true) AS paid_amount_cents',
          'SUM(invoices.amount_cents) FILTER (WHERE invoices.paid = false) AS unpaid_amount_cents'
        )
    end

    # conventiance method so that you don't need to call
    # Users::IndexQuery.new(users).call
    def self.call(users)
       new(users).call
    end
  end
end

但是老实说，我不明白为什么你会将它提取到它自己的对象中，而不是仅仅在模型中创建一个作用域/类方法，因为这是一个非常复杂的解决方案。
你能添加IndexQuery类吗？@SebastianPalma添加到OP中。
User.default\u scopes
返回什么？@SebastianPalma它返回一个空数组[]@塞巴斯蒂安·帕尔玛，我想我找到了。它是IndexQuery开头的.created_desc作用域，按用户排序。id作用域：created_desc，->{order（id:：desc）}。非常感谢。
# see https://github.com/rubocop/ruby-style-guide#namespace-definition
module  Users
  class IndexQuery
    def initialize(users)
      @users = users
    end

    def call
      @users.kept.created_desc
        .joins(:invoices)
        .group(:id)
        .select(
          User.arel_table[:*],
          'SUM(invoices.amount_cents) FILTER (WHERE invoices.paid = true) AS paid_amount_cents',
          'SUM(invoices.amount_cents) FILTER (WHERE invoices.paid = false) AS unpaid_amount_cents'
        )
    end

    # conventiance method so that you don't need to call
    # Users::IndexQuery.new(users).call
    def self.call(users)
       new(users).call
    end
  end
end