ruby-on-rails - 按在 Postgresql 和 Ruby On Rails 中创建的顺序显示连接记录数据

Question

我在 postgresql 数据库中有三个表:

1. 成员

   • 编号
   • 名字
   • 姓氏
   • 创建于

2. 付款(如借记)

   • 编号
   • 成员(member)编号
   • 数量
   • 创建于
   • 输入

3. 费用(如学分)

   • 编号
   • 成员(member)编号
   • 数量
   • 创建于
   • 输入

我想在单一 View 中显示它们，比如帐单:我使用了以下查询:

select * from members as t1 left join payments as t2 on (t1.id=t2.member_id) left join fees as t3 on (t1.id=t3.member_id) 

它显示了以下结果:

id | Amount | created_at | Type
1   100      25-12-2013   Fee
2   100      29-12-2013   Fee
3   100      25-12-2013   Payment
4   100      23-12-2013   Payment

但问题是它首先显示费用记录，然后在我需要时显示付款，它应该由 created_at 订购，它应该如下所示:

id | Amount | created_at | Type
1   100      23-12-2013   Payment
2   100      25-12-2013   Fee
3   100      25-12-2013   Payment
4   100      29-12-2013   Fee

这里是模型的详细信息:

class Fee < ActiveRecord::Base

  # Setup accessible (or protected) attributes for your model
  attr_accessible :member_id,:fee_type,:amount,:reason,:details,:date

  # Setup relations with relative models
  belongs_to :member

  # Validates rule here
  validates_numericality_of :member_id,:fee_type,:amount

  validates :reason,
    :format => {:with => /^[-a-zA-Z0-9_ ]+$/ },
    :length => {:maximum => 255},
    :presence =>true
  validates :details,
    :format => {:with => /^[-a-zA-Z0-9_ ]+$/ },
    :length => {:maximum => 255},
    :allow_blank =>true
  validates :amount,
    :presence => true
  validates :member_id,
    :presence => true
  validates :date,
    :presence => true

  # Search start here
  self.per_page = 10

end

class Payment < ActiveRecord::Base

  # Setup accessible (or protected) attributes for your model
  attr_accessible :member_id,:payment_category_id,:payment_type_id,:payment_date,:amount,:notes,:is_send_email,:last_sent,:date_deposite
  # Setup relations with relative models 
  belongs_to :payment_type
  belongs_to :payment_category
  belongs_to :member

  # Validates rule here
  validates_numericality_of :member_id,:payment_category_id,:payment_type_id,:amount

  validates :notes,
    :format => {:with => /^[-a-zA-Z0-9_ ]+$/ },
    :length => {:maximum => 255},
    :allow_blank =>true
  validates :amount,
    :presence => true,
    :length => {:maximum => 15}
  validates :member_id,
    :presence => true
  validates :payment_date,
    :presence => true

  # Pagiination start here
  self.per_page = 10

end

class Member < ActiveRecord::Base

  has_many :payment, dependent: :destroy, -> { order :created_at }
  has_many :fee, dependent: :destroy, -> { order :created_at }
  has_many :events, :through => :participants

end

Answer 1

如果我是你，我会使用 ActiveRecord Associations像这样:

#app/models/member.rb
Class Member < ActiveRecord::Base
   has_many :payments, -> { order :created_at }
   has_many :fees, -> { order :created_at }
end

#app/models/payment.rb
Class Payment < ActiveRecord::Base
   belongs_to :member
end

#app/models/fee.rb
Class Fee < ActiveRecord::Base
   belongs_to :member
end

这应该让您能够按顺序提取所需的关联数据，如下所示:

@member = Member.find 1
@member.payments #-> should be ordered by created_at