/*******************************************************************************
* Copyright (c) 2012, 2015 Oracle and/or its affiliates. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Oracle - initial API and implementation
*
******************************************************************************/
package org.eclipse.persistence.jpa.jpql.tools.resolver;
import org.eclipse.persistence.jpa.jpql.ExpressionTools;
/**
* This <code>DerivedDeclaration</code> represents an identification variable declaration that was
* declared in the <code><b>FROM</b></code> clause of a <code><b>SELECT</b></code> subquery. The
* "root" object is not an entity name but a derived path expression.
*
* @see org.eclipse.persistence.jpa.jpql.parser.IdentificationVariableDeclaration IdentificationVariableDeclaration
*
* @version 2.5
* @since 2.5
* @author Pascal Filion
*/
public class DerivedDeclaration extends AbstractRangeDeclaration {
/**
* Creates a new <code>DerivedDeclaration</code>.
*/
public DerivedDeclaration() {
super();
}
/**
* If {@link org.eclipse.persistence.jpa.jpql.parser.CollectionMemberDeclaration#isDerived()} is
* <code>true</code>, then returns the identification variable used in the derived path expression
* that is defined in the superquery, otherwise returns an empty string.
*
* @return The identification variable from the superquery if the root path is a derived path
* expression
*/
public String getSuperqueryVariableName() {
int index = rootPath.indexOf('.');
return (index > -1) ? rootPath.substring(0, index) : ExpressionTools.EMPTY_STRING;
}
/**
* {@inheritDoc}
*/
public Type getType() {
return Type.DERIVED;
}
}