Question

我在postgresql数据库中有三个表：

成员
- ID
- 如first_name
- 姓氏
- created_at
付款（如借记卡）
- ID
- member_id
- 金额
- created_at
- 型
费用（如信用证）
- ID
- member_id
- 金额
- created_at
- 型

我想在单个视图中显示他们的结算声明：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，它显示了第一笔费用记录，然后付款，而我需要它应该是由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

以下是模型的详细信息：

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，我会像这样使用ActiveRecord Associations：

#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

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

Answer 2

根据您提取的记录数量，您还可以在将数据库拉出数据库后进行ruby排序，例如

transactions = member.payments + member.fees
transactions = transactions.flatten.sort_by(&:created_at)

按照在Postgresql和Ruby On Rails中创建的顺序显示连接记录数据

2 个答案: