如何在join/eager_load中查找default_scope？

我有兩個型號：如何在join/eager_load中查找default_scope？

class User 
    default_scope -> { where(deleted_at: nil) } 
end 

class Order 
    belongs_to :user 
end

而且我想用刪除或不刪除用戶訂單：這些工作

Order.joins(:user).merge(User.unscoped) 
Order.joins(:user).merge(User.unscope(where: :deleted_at)) 
# SELECT "orders".* FROM "orders" 
# INNER JOIN "users" ON "users"."id" = "orders"."user_id" AND "users"."deleted_at" IS NULL 
# ORDER BY "orders"."id" DESC LIMIT 1 

Order.eager_load(:user).merge(User.unscoped) 
Order.eager_load(:user).merge(User.unscope(where: :deleted_at)) 
# SELECT "orders"."id" AS t0_r0, "orders"."user_id" AS t0_r1, 
# "users"."id" AS t1_r0, "users"."deleted_at" AS t1_r1 FROM "orders" 
# LEFT OUTER JOIN "users" ON "users"."id" = "orders"."user_id" AND "users"."deleted_at" IS NULL 
# ORDER BY "orders"."id" DESC LIMIT 1

無。

每個查詢都將「AND」用戶「。」deleted_at「IS NULL」添加到聯接語句中。

不會做改變，如果我指定的關聯範圍：

class Order 
    belongs_to :user, -> { unscoped } 
end

但是包括按預期工作：

Order.includes(:user).merge(User.unscoped).last 
# SELECT "orders".* FROM "orders" ORDER BY "orders"."id" DESC LIMIT 1 
# SELECT "users".* FROM "users" WHERE "users"."id" = 1054

如何使導軌在加入unscope關聯？

來源

2016-12-01 Anton

你可以試試這個。它適用於Rails 3，但不知道Rails 4.

User.unscoped { Order.joins(:user) }

來源

2016-12-01 13:18:11

它仍然有效：http://api.rubyonrails.org/classes/ActiveRecord/Scoping/Default/ClassMethods.html ＃method-i-unscoped – lcguida

謝謝。但是，如果我有多重關係來取景，我不得不多次包裝它。我想知道這是否可以用其他方式完成？ – Anton

我通過手動編寫連接查詢來解決此問題。對於你的情況應該是這樣的：

Order.joins('INNER JOIN users ON users.id=orders.user_id')

雖然Order.includes(:user).merge(User.unscoped)解決方案，你發現了，看起來有點更好，除非你真的想只有一個查詢

來源

2017-07-06 16:32:48 divideByZero

您可以在同一個模型來定義另一個關聯特別針對那些已刪除的用戶：

此示例假定您使用act-as-paranoid來處理軟刪除。

class Order 
    belongs_to :user 
    belongs_to :all_user, -> { with_deleted }, foreign_key: 'user_id' 
end

然後選擇你的武器：

Order.includes(:user).pluck(:email)  # Only non soft-deleted emails 
Order.includes(:all_user).pluck(:email) # All emails including where deleted_at is null

```

來源

2017-10-26 21:48:57 NNA

如何在join/eager_load中查找default_scope？

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