如何获取DB序列生成的新对象ID？

Question

I have table with sequence and trigger so it creates new id when inserting it to the DB.

How can I get the new object id, before calling SaveChanges()?

I need this id for the links between the new object and other objects.

I want to do it before calling SaveChanges because I want to have the option to rollback.

Answer 1

You can't get it without calling SaveChanges() . Think about it. The ID comes from the DB. SaveChanges() is the first thing which causes communication with the DB.

If you want to undo, you have several choices:

• In many cases, you don't need to know the ID client-side when inserting. Simply creating the relationship is enough.
• Use a client-generateable ID like a GUID.
• Use TransactionScope for a "real" DB transaction.
• Do an undo ( DeleteObject ) instead of a rollback.