"在设定变更]中检测到循环;当试图圆链表添加到数据库 [英] "A cycle was detected in the set of changes" When trying to add a circularly linked list to the database
问题描述
我使用的是数据库循环链表（CLL）。我插入形成使用LINQ to SQL执行这些CLL的数据库条目。
I'm using a 'in database' circularly linked list (cll). I'm inserting the database entries forming these cll's using Linq to Sql.
他们的一般形式：
id uuid | nextId uuid | current bit
如果我尝试做一个的SubmitChanges与几个对象形成了完整的CLL，我得到的错误的组更改检测到循环。
If i try to do a SubmitChanges with a few objects forming a complete cll, i get the error "A cycle was detected in the set of changes".
我可以通过在一个单独的SubmitChanges链表通知绕过这个，但这样做有两个倒边：我失去了我的能力在一个做到这一点交易。对于一个小的时间在我的数据库中的数据是不正确的。
I can circumvent this by making the linked list 'circular' in a separate SubmitChanges, but this has two down sides: I'm losing my capability to do this in one transaction. For a small period the data in my database isn't correct.
有没有办法来解决这个问题？
Is there a way to fix this behaviour?
推荐答案
数据库需要强制执行的约束上，和我想象你有 nextId 和C>标识。如果这条产业链关系，导致回到起点（如你发现）数据库不会允许它
The database needs to enforce its contraints, and I imagine you have a foreign key constraint between nextId and Id. If this chain of relations leads back to the start (as you have found) the database will not allow it.
我怀疑你的选择是：
- 删除外键约束。
- 存储在数据库中的一个链接列表，并只能加入同尾头在你的代码。
即使你的第二个选项将不起作用，因为DB不会允许你添加这最后引用。
Even your second option won't work, as the DB won't allow you to add this last reference.
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