The database that is the target of the operation.
- iOS 8.0+
- macOS 10.10+
- tvOS 9.0+
- watchOS 3.0+
For operations you plan to execute from your own custom queue, use this property to specify the target database. Setting the database also sets the corresponding container, inherited from the
CKOperation parent class. If the value of this property is
nil, the operation targets the private database of the app’s default container.
The default value of this property is