When a non-nullable attribute's datatype is converted to a non-primitive datatype (such as class NSNumber, NSDate, and so on), you must verify that the the corresponding property for the MBO instance is assigned a non-nil value, otherwise the application may receive a runtime exception when creating a new MBO instance.
A typical scenario is when an attribute exists in ASE's identity column with a numeric datatype. For example, for a non-nullable attribute with a decimal datatype, the corresponding datatype in the generated Objective-C MBO code is NSNumber. When creating a new MBO instance, ensure that you assign this property a non-nil value.