如何在Entity Framework CF之前删除子实体？ [英] How to delete child entities before parent with Entity Framework CF?

问题描述

我试图使用EF代码，首先删除一个数据库记录（ deleteMe ）和它的孩子（ deleteMe.Prices ）。

I am trying to use EF code-first to delete a db record (deleteMe) and it's children (deleteMe.Prices).

foreach (var deleteMe in deleteThese)
{ 
   // Delete validation
   if(CanDeleteItem(deleteMe.ItemId))
   {
      db.Entry(deleteMe).State = EntityState.Deleted;

      foreach (var item in deleteMe.Prices)
      {
         db.Entry(item).State = EntityState.Deleted; // cascade delete
      }
   }
}
db.SaveChanges();

但是，Entity Framework似乎无法跟踪子记录应该在父母。我收到错误：

However, Entity Framework seems to be unable to track the fact that the child records should be deleted before the parent. I get the error:

DELETE语句与REFERENCE约束ItemPrice_Item冲突。

冲突发生在数据库DEVDB，表dbo.ItemPrices，
列Item_ItemId。

语句已终止。

The DELETE statement conflicted with the REFERENCE constraint "ItemPrice_Item".
The conflict occurred in database "DEVDB", table "dbo.ItemPrices", column 'Item_ItemId'.
The statement has been terminated.

我如何在EF中执行这个删除？

How would I execute this delete in EF?

推荐答案

d为我做：

foreach (var deleteMe in deleteThese)
{ 
   // Delete validation
   if(CanDeleteItem(deleteMe.ItemId))
   {
      ///
      deleteMe.Prices.ToList().ForEach(p => db.ItemPrices.Remove(p));
      ///

      db.Entry(deleteMe).State = EntityState.Deleted;
   }
}
db.SaveChanges();

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