如何比较Rails中两个不同表格的两行3.2.8

Question

我需要将一个包含6个属性的包含6个属性的包含6个属性的获奖数据表中的7行属性与另一个表中的1行或多行进行比较。从结果中，我想计算一个表中匹配另一个表的属性数量并呈现结果。

我有两个型号：lottery_selections & winning_numbers

# == Schema Information 
# 
# Table name: lottery_selections 
# 
# id      :integer   not null, primary key 
# syndicate_id   :integer 
# lottery_selection_1 :integer 
# lottery_selection_2 :integer 
# lottery_selection_3 :integer 
# lottery_selection_4 :integer 
# lottery_selection_5 :integer 
# lottery_selection_6 :integer 
# lottery_selection_date :datetime 
# created_at    :datetime   not null 
# updated_at    :datetime   not null 
# 

class LotterySelection < ActiveRecord::Base 
    attr_accessible :lottery_selection_1, :lottery_selection_2, :lottery_selection_3, :lottery_selection_4,\ 
    :lottery_selection_5, :lottery_selection_6, :lottery_selection_date, :syndicate_id 
    belongs_to :winning_number 

    #validates_associated :winning_number 
    validates :lottery_selection_1, :lottery_selection_2, :lottery_selection_3, :lottery_selection_4,\ 
    :lottery_selection_5, :lottery_selection_6, :presence => true, :numericality => {:greater_than_or_equal_to => 1}, \ 
    :numericality => {:less_than_or_equal_to => 49} 

UNIQU_FIELDS = [:lottery_selection_1, :lottery_selection_2, :lottery_selection_3, :lottery_selection_4,\ 
:lottery_selection_5, :lottery_selection_6] 

validate :lottery_numbers_are_unique 

def lottery_numbers_are_unique 
    unless UNIQU_FIELDS.map{|field| self[field] }.uniq.length == UNIQU_FIELDS.length 
     errors[:base] << "You have repeated one or more numbers for that day's draw" 
    end 
    end 
end 

# == Schema Information 
# 
# Table name: winning_numbers 
# 
# id     :integer   not null, primary key 
# winning_numbers_date :datetime 
# winning_number_1  :integer 
# winning_number_2  :integer 
# winning_number_3  :integer 
# winning_number_4  :integer 
# winning_number_5  :integer 
# winning_number_6  :integer 
# winning_number_bonus :integer 
# created_at   :datetime   not null 
# updated_at   :datetime   not null 
# 

class WinningNumber < ActiveRecord::Base 
    attr_accessible :winning_number_1, :winning_number_2, :winning_number_3, :winning_number_4, :winning_number_5,\ 
    :winning_number_6, :winning_number_bonus, :winning_numbers_date 
    has_many :lottery_selections 
    #validates_associated :lottery_selections 
     validates :winning_number_1, :winning_number_2, :winning_number_3, :winning_number_4, :winning_number_5,\ 
    :winning_number_6, :winning_number_bonus, :presence => true, :numericality => {:greater_than_or_equal_to => 1}, \ 
    :numericality => {:less_than_or_equal_to => 49} 

    #Below checks that for any given date there can only be one set of winning numbers 
    validates :winning_numbers_date, uniqueness: { scope:  [:winning_number_1, :winning_number_2, :winning_number_3,\ 
    :winning_number_4, :winning_number_5, :winning_number_6, :winning_number_bonus] } 


    UNIQ_FIELDS = [:winning_number_1, :winning_number_2, :winning_number_3, :winning_number_4, :winning_number_5, :winning_number_6, :winning_number_bonus] 

    validate :winning_numbers_are_unique 

    def winning_numbers_are_unique 
     unless UNIQ_FIELDS.map{|field| self[field] }.uniq.length == UNIQ_FIELDS.length 
     errors[:base] << "You have repeated one or more numbers for that day's draw" 
     end 
    end 
end 

你能请告知我如何作出比较，并使用结果来呈现的结果？

Answer 1

最有效的解决方案（甚至更多的rails开发人员会建议不要这样做）：在数据库上创建一个存储过程，您可以在其中进行比较并返回结果。

东西快，你可以做（​​尽管你越研究越好，对彩票的应用程序，你可以有大把的票子，而你需要运行的东西是真正有效的）：

winning_numbers = # Do a query and put the array of winning numbers here 

seven_numbers_match = LotterySelection.where("number_1 in (?) and number_2 in (?) and number_3 in (?) and number_4 in (?) and number_5 in (?) and number_6 in (?) and number_7 in (?)", winning_numbers, winning_numbers, winning_numbers, winning_numbers, winning_numbers, winning_numbers, winning_numbers) 

six_number_match = LotterySelection.where("(number_1 in (?) and number_2 in (?) and number_3 in (?) and number_4 in (?) and number_5 in (?) and number_6 in (?) and number_7 not in(?)") OR (number_1 in (?) and number_2 in (?) and number_3 in (?) and number_4 in (?) and number_5 in (?) and number_6 not in (?) and number_7 in (?)) OR (...") 

等等它可能不是最好的算法，但它的工作原理和使用数据库引擎来做同情。

但是，对于这样的问题，我绝对会雇用一位DBA顾问为我写存储过程。