这是我的dat模型：
>>> scipy.interpolate.interp1d(x, y, kind='cubic')(1.5)
array(1.265624999999932)
我在私人队列MOC上创建地址。
当我写这篇文章时：
Contact.address————(optional = true, delete rule = cascade)—————>>Address
Address.contact————(optional = false, delete rule = nullify)—————>Contact
Address. apartment———————(optional = true, delete rule = cascade)———>Apartment
Address.landmarks————(optional = true, delete rule = cascade)———>>Landmark
它给了我这个错误：
contact.address = nil <— I am hoping that doing so will delete address entity from database
moc.save() <— main thread MOC
原因是什么？
我认为Error Domain=NSCocoaErrorDomain Code=1570 "The operation couldn’t be completed. (Cocoa error 1570.)" UserInfo=0x7fa3f2dafc20 {NSValidationErrorKey=contact, NSLocalizedDescription=The operation couldn’t be completed. (Cocoa error 1570.), NSValidationErrorObject=<PROJ.Address: 0x7fa3f2f9bbf0> (entity: Address; id: 0xd000000000040008 <x-coredata://E756D530-F841-4F78-AC7F-C50BE4DB88BD/XmppContact/p1> ; data: {
street = Bla Bla Road;
contact = nil;
apartment = "0xd00000000004000a <x-coredata://E756D530-F841-4F78-AC7F-C50BE4DB88BD/Apartment/p1>";
landmarks = "<relationship fault: 0x7fa3f2e70f80 'landmarks’>”;
})}
是零，这就是它显示错误的原因
如果是，那么如何从contact删除address？