Question

如果有人能帮助我写一个显示参加活动的女性（女性）人数的范围，我真的很感激。

模型

user.rb

belongs_to :category_gender
has_many :payments

category_gender.rb

has_many :users

event.rb

belongs_to :user
has_many :payments

payment.rb

belongs_to :user
belongs_to :event

终端

event = Event.find(7)
event_payments = event.payments

2.3.0 :054 > event_payments
[
    [0] #<Payment:0x007fea72ac5b70> {
                               :id => 6,
                            :email => "richill@gmail.com",
                          :user_id => 4,
                        :reference => "SPz_ruZ5om",
                       :created_at => Wed, 16 Nov 2016 13:52:23 UTC +00:00,
                       :updated_at => Wed, 16 Nov 2016 13:52:23 UTC +00:00,
                         :event_id => 7,
               :stripe_customer_id => "cus_9YuZZAniFCZVxn",
                :stripe_payment_id => "ch_19GTpnAAe71J3vK0aj1gKryO",
               :event_payment_date => Wed, 16 Nov 2016 13:52:23 UTC +00:00,
                           :status => "success"
    }
    [1] #<Payment:0x007fea72ac5b70> {
                               :id => 7,
                            :email => "peter@gmail.com",
                          :user_id => 5,
                        :reference => "SPz_mnX4ul",
                       :created_at => Wed, 16 Nov 2016 13:52:23 UTC +00:00,
                       :updated_at => Wed, 16 Nov 2016 13:52:23 UTC +00:00,
                         :event_id => 7,
               :stripe_customer_id => "cus_6FhLLMotYCCYvn",
                :stripe_payment_id => "ch_20GTunDDt87J3vK1sp4gPry9",
               :event_payment_date => Wed, 16 Nov 2016 13:52:23 UTC +00:00,
                           :status => "success"
    }
]

如何编写范围以查找女性在某项活动中支付的所有款项？

如果我写下面的话，我可以找到女人的第一笔付款：

event.payments.first.user.category_gender.name

2.3.0 :026 > event.payments.first.user.category_gender.name
  Payment Load (0.2ms)  SELECT  "payments".* FROM "payments" WHERE "payments"."event_id" = ?  ORDER BY "payments"."id" ASC LIMIT 1  [["event_id", 7]]
  User Load (0.1ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = ? LIMIT 1  [["id", 4]]
  CategoryGender Load (0.1ms)  SELECT  "category_genders".* FROM "category_genders" WHERE "category_genders"."id" = ? LIMIT 1  [["id", 2]]
 => "Female"

我尝试了以下范围来显示女性为某项活动支付的所有款项，但没有运气 - 尝试了一种方法，但没有运气。非常感谢您的帮助和解释，将其作为范围和方法撰写：

event.rb

scope :females, -> { joins(payment: :category_gender).where('category_genders.name' => "Female") }

def females
  self.payments.where('user.category_gender.name = ?', "Female")
end

错误消息：

2.3.0 :004 >   event.females
  Payment Load (1.7ms)  SELECT "payments".* FROM "payments" WHERE "payments"."event_id" = ? AND (user.category_gender.name = 'Female')  [["event_id", 7]]
SQLite3::SQLException: no such column: user.category_gender.name: SELECT "payments".* FROM "payments" WHERE "payments"."event_id" = ? AND (user.category_gender.name = 'Female')
ActiveRecord::StatementInvalid: SQLite3::SQLException: no such column: user.category_gender.name: SELECT "payments".* FROM "payments" WHERE "payments"."event_id" = ? AND (user.category_gender.name = 'Female')

Answer 1

class Payment
  scope :by_females, -> { joins(user: :category_gender).where(category_genders: { name: 'Female' }) }
end

现在使用方便：

event.payments.by_females

协会的范围 - Rails 4

1 个答案: