On 2011 Feb 10, at 18:37, Gordon Apple wrote: > The error handles gives 10 console messages, "The operation couldn’t be > completed", which is the exact number of records in the test database. So > something is definitely going awry in the mapping.
Log these errors' -userInfo. In particular, look for an NSUnderlyingErrorKey. > OK. I've identified the problem. The one new entity relationship in > mainEntity is not optional. Changing it to optional allows lightweight > migration to work. I **never** use non-optional properties, because of all the corner cases I've seen while the object is being built up or torn down, and Core Data finds a non-optional property to be missing and has a seizure. > However, that has its own issues. I had it non-optional > for a reason. It is essential in the new database. Well, then, write your own code to do the validation. Another reason not to use non-optional properties (Core Data's built-in validation) is because when Core Data finds such a property missing, it *displays* an error dialog with an inexplicable message to your user. No. Write your own validation code and handle your own validation errors. _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
