/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * 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.
 */
package javax.jdo.query;

/**
 * Expression representing a persistable object in a query (e.g alias.persistableField).
 *
 * @param <T> (Persistable) Java type being represented here
 */
public interface PersistableExpression<T> extends Expression<T> {
  /**
   * Method to return an expression for the (JDO) identity of this persistable object.
   *
   * @return The identity expression
   */
  Expression<?> jdoObjectId();

  /**
   * Method to return an expression for the (JDO) version of this persistable object.
   *
   * @return The version expression
   */
  Expression<?> jdoVersion();
}