* Copyright 2007 Daniel Spiewak
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
Marks a specific field as to be constrained to non-NULL values within
the database. This functionality is handled through the schema indicating
to the database that the constraint should be enforced. ActiveObjects
itself does no checking to ensure that the value of the field can only
be non-NULL. For most databases, this means that the field corresponding
to the method in question will be defined with the
This annotation is only relevant to migrations. It has no effect upon "runtime" entity usage.