当我更新我的sqlite核心数据存储时，如何避免在SQL执行期间出现“错误：约束失败”？

Our app lets the user choose a location from a list which is provided by an API. The list updates infrequently and only by adding items, so instead of hitting the API every time, the app comes with a snapshot in a Core Data sqlite store, and we want it to periodically update the list. The code to do so works like this:Our app lets the user choose a location from a