/******************************************************************************* | |
* Copyright (c) 1998, 2013 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 from Oracle TopLink | |
******************************************************************************/ | |
package org.eclipse.persistence.internal.jpa.parsing; | |
/** | |
* INTERNAL | |
* <p><b>Purpose</b>: Superclass for Aggregate Nodes | |
* <p><b>Responsibilities</b>:<ul> | |
* <li> Apply itself to a query correctly | |
* </ul> | |
* @author Jon Driscoll | |
* @since TopLink 5.0 | |
*/ | |
import org.eclipse.persistence.expressions.Expression; | |
public abstract class AggregateNode extends Node implements AliasableNode { | |
private boolean distinct = false; | |
/** | |
* INTERNAL | |
*/ | |
public String resolveAttribute() { | |
Node arg = getLeft(); | |
return arg.isDotNode() ? ((DotNode)arg).resolveAttribute() : null; | |
} | |
/** | |
* resolveClass: Answer the class associated with my left node. | |
*/ | |
public Class resolveClass(GenerationContext context) { | |
return getLeft().resolveClass(context); | |
} | |
/** | |
* INTERNAL | |
* Is this node an Aggregate node | |
*/ | |
public boolean isAggregateNode() { | |
return true; | |
} | |
/** */ | |
public boolean usesDistinct() { | |
return distinct; | |
} | |
/** */ | |
public void setDistinct(boolean distinct) { | |
this.distinct = distinct; | |
} | |
/** | |
* INTERNAL | |
* Return a EclipseLink expression generated using the left node | |
*/ | |
public Expression generateExpression(GenerationContext context) { | |
if (alias == null){ | |
alias = getAsString(); | |
} | |
Expression aggregateExpr = context.expressionFor(alias); | |
if (aggregateExpr == null) { | |
Expression arg = getLeft().generateExpression(context); | |
if (usesDistinct()) { | |
arg = arg.distinct(); | |
} | |
aggregateExpr = addAggregateExression(arg); | |
context.addExpression(aggregateExpr, alias); | |
} | |
return aggregateExpr; | |
} | |
/** | |
* INTERNAL | |
*/ | |
protected abstract Expression addAggregateExression(Expression expr); | |
public boolean isAliasableNode(){ | |
return true; | |
} | |
} |