Cannot add an entity with a key that is already in use

dc.TongJi_Qis.DeleteAllOnSubmit(v);
  dc.SubmitChanges();


后

dc.TongJi_Qi_JiBens.InsertOnSubmit(xx);
  dc.SubmitChanges();//出错


Cannot add an entity with a key that is already in use


我看了表，记录被删除了。

------解决方法--------------------------------------------------------
是不是插入的主键值重复了呢？