从 table（级联）中删除具有 2 个外键的行

Question

我有下一个table结构：

RoomId 和 HouseId 可以为空，一个字段始终为空。我在尝试从 Houses table.

中删除行时遇到下一个异常

The DELETE statement conflicted with the REFERENCE constraint "FK_dbo.Images_dbo.Rooms_RoomId"

为什么级联删除失败？我先用了EF码。

编辑

基于@Juan Carlos 示例的工作触发器：

BEGIN TRANSACTION

   delete from images 
   where houseId in ( select id from deleted )

   delete from images 
   where roomId in ( 
                       select rooms.Id
                       from rooms 
                       where rooms.HouseId in (select id from deleted)
                   )

   delete from Rooms 
   where houseId in ( select id from deleted )

   delete from houses 
   where ID in ( select ID from deleted )

COMMIT

Answer 1

问题是级联顺序。您已遵循以下顺序：

删除房间
删除图片
删除房屋

你需要创建一个触发器来解决这个问题。现在的问题是我不知道如何使用 Code First 创建它。

create trigger house_cascade
on Houses
instead of delete
as
   set nocount on
   delete from rooms
   where room.id in (select i.ID 
                     from images i
                     inner join deleted d
                        on i.house_id = d.id)

   delete from images 
   where house_id in ( select id from deleted )

   delete from houses 
   where ID in ( select ID from deleted )

更多信息here

尤其是这条评论

But SQL Server doesn't support this. It's supper annoying, no other serious DB engine has this problem, people complained about it in 2005, Microsfot agreed that it was a "desirable feature" in 2008, but still here in 2014 they don't have it. – Shavais Aug 5 '14 at 21:28

从 table（级联）中删除具有 2 个外键的行

Remove row from table (cascade) that have 2 foreign keys

sql

entity-framework

foreign-keys

cascade