Rails - 銷燬'連接表'協會

Question

我想知道是否有軌道方式來銷燬has_many關聯，給定一個條件。 買家

class Buyer < ActiveRecord::Base 
    has_many :phones, as: :phoneable, dependent: :destroy, class_name: 'Telephone' 
end 

電話

class Telephone < ActiveRecord::Base 
    belongs_to :phoneable, polymorphic: true 
end 

我想加入與電話買家，並銷燬所有電話where('buyers.tel = telephones.number')。寫這個查詢的最好方法是什麼？

Answer 1

，如果你處理的是隻有1 Buyer記錄：

buyer = Buyer.first 
buyer.phones.where('number = ?', buyer.tel).destroy_all 

如果對所有Buyers：

# XXX this will select all buyers you want but in your case you want to destroy the phones not the buyers so we need the reverse one check next: 
Buyer.joins(:phones).where("buyers.tel = telephones.number") 

# but this one will as we need the reverse relation: 
Telephone.where("phoneable_type = 'Buyer' and buyers.tel = telephones.number").includes(:phoneable) 

報告中，我們添加phoneable_type = 'Buyer'你有一個多態關係的情況和你你只需要爲Buyer創建一個