I’m currently running a Core Data app in Xcode and trying to figure out why an object tells me that the value of its ‘foo’ attribute is nil, but when I query the SQLite file on disk, the value of the ‘ZFOO’ attribute for the problem object is a short string, not nil.
There is only one managed object context with this store, and it was created on the main thread. The value of ‘foo’ was pre-existing in the store when the app launched and should not have been changed. The app gives me three indications that foo is nil… • app’s user interface indicates that foo is nil. • Using lldb’s expr command, [problemObject foo] returns nil • Creating a fetch request in lldb, sending -[NSManagedObjectContext executeFetchRequest:error:] returns descriptions of the data for 4 objects as expected; all look good except that the problem object has foo=nil. I’ve also tried in lldb: • -[NSManagedObjectContext save:] • -[NSManagedObjectContext refreshObject:problemObject mergeChanges:YES] • -[NSManagedObjectContext processPendingChanges] All methods executed OK but did not change any of the results. Executing an ‘update’ query with another program upon the SQLite file, I changed a different attribute of the problem object. Upon re-executing the fetch request in lldb, the problem object was now a fault. I then sent [myObject foo], which still returned nil, but this apparently caused the data to be “faulted in”, because a subsequent fetch request in lldb no longer showed a fault, but now showed all of the old data. That is, foo=nil still, and the different attribute was still at its old value. Do I misunderstand how this stuff is supposed to work? Thanks, Jerry _______________________________________________ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
