如何在Rails中收集？

Question

baza_managers = BazaManager.find(:all, 
    :conditions => ["or_unit_id != ?", 1]).collect { 
     |mou| [mou.email, mou.or_unit_id]} 

respondent_emails = Respondent.find(:all).collect {|r| r.email } 

錯誤：

from lib/scripts/baza_sync.rb:26:in `each' 
from lib/scripts/baza_sync.rb:26 

26線↓

baza_managers.each do |moi| 
    if !respondent_emails.include?(moi) 
    Respondent.create(:email => moi, :user_id => 1, :respondent_group_id => moi) 
    end 
end 

錯誤，我得到：

undefined method `email' for ["vadasd@test.test.com", 8]:Array (NoMethodError) 

我不知道爲什麼我得到這個錯誤。

Answer 1

嘗試：

baza_managers = BazaManager.find(:all, 
    :conditions => ["or_unit_id != ?", 1]).collect { 
     |mou| [mou.email, mou.or_unit_id]} 

respondent_emails = Respondent.find(:all).collect {|r| r.email } 

baza_managers.each do |moi| 
    if !respondent_emails.include?(moi[0]) 
    Respondent.create(:email => moi[0], :user_id => 1, :respondent_group_id => moi[1]) 
    end 
end 

Answer 2

用以下解決您的代碼：

if !respondent_emails.include?(moi[0]) 
    Respondent.create(:email => moi[0], :user_id => 1, :respondent_group_id => moi[1]) 
end 

Answer 3

我認爲至少有一個錯誤不是你正在使用collect的方式，但在你寫的邏輯在通過baza_managers陣列時最後一行。

這段代碼的條件respondent_emails.include?(moi)將永遠假的，因爲respondent_emails是電子郵件地址的數組，但moi就像["vadasd@test.test.com", 8]數組所以他們永遠不會匹配。

我覺得這個錯誤讓你做該行的錯誤：

Respondent.create(:email => moi, :user_id => 1, :respondent_group_id => moi) 

因爲這條線將被計算爲（例如）：

Respondent.create(:email => ["vadasd@test.test.com", 8], :user_id => 1, :respondent_group_id => ["vadasd@test.test.com", 8]) 

這可能不是你想要的。

最後，我建議你閱讀the debugger rails guide，我經常用調試器來弄清楚這種代碼和錯誤在哪裏以及是什麼問題。

Answer 4

如下我將重寫代碼：

baza_managers = BazaManager.all(:conditions => ["or_unit_id != ?", 1]). 
        collect { |mou| [mou.email, mou.or_unit_id]} 

respondent_emails = Respondent.find(:all).collect {|r| r.email } 

baza_managers.each do |email, unit_id| 
    unless respondent_emails.include?(email) 
    Respondent.create(:email => email, :user_id => 1, 
     :respondent_group_id => unit_id) 
    end 
end 

該解決方案可以通過使用OUTER JOIN檢測丟失Respondents

BazaManager.all(
    :include => "OUTER JOIN respondents A ON baza_managers.email = A.email", 
    :conditions => ["baza_managers.or_unit_id != ? AND A.id IS NULL", 1] 
).each do |bm| 
    Respondent.create(:email => bm.email, :respondent_group_id => bm.or_unit_id, 
    :user_id => 1) 
end   

該解決方案將進一步優化可以通過添加associations作出優雅和最優和named_scope。

class BazaManager 

    has_many :respondents, :foreign_key => :email, :primary_key => :email 

    named_scope :without_respondents, :include => :respondents, 
    :conditions =>["baza_managers.or_unit_id != ? AND respondents.id IS NULL", 1] 

end 

現在named_scope可以用如下：

BazaManager.without_respondents.each do |bm| 
    Respondent.create(:email => bm.email, :respondent_group_id => bm.or_unit_id, 
    :user_id => 1) 
end