/******************************************************************************* | |
* 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: | |
* tware - initial implementation as part of JPA 2.0 RI | |
******************************************************************************/ | |
package org.eclipse.persistence.internal.jpa.parsing; | |
import org.eclipse.persistence.expressions.Expression; | |
import org.eclipse.persistence.queries.ObjectLevelReadQuery; | |
import org.eclipse.persistence.queries.ReportQuery; | |
/** | |
* INTERNAL | |
* <p><b>Purpose</b>: Represent an NULLIF in EJBQL | |
* <p><b>Responsibilities</b>:<ul> | |
* <li> Generate the correct expression for an NULLIF in EJBQL | |
* </ul> | |
* @author tware | |
* @since EclipseLink 1.2 | |
*/ | |
public class NullIfNode extends Node implements AliasableNode { | |
public NullIfNode(){ | |
super(); | |
} | |
/** | |
* INTERNAL | |
* Apply this node to the passed query | |
*/ | |
public void applyToQuery(ObjectLevelReadQuery theQuery, GenerationContext generationContext) { | |
if (theQuery instanceof ReportQuery) { | |
ReportQuery reportQuery = (ReportQuery)theQuery; | |
Expression expression = generateExpression(generationContext); | |
reportQuery.addItem("NullIf(" + getLeft().getAsString() + "," + getRight().getAsString() + ")", expression); | |
} | |
} | |
/** | |
* INTERNAL | |
* Generate the a new EclipseLink NullIf expression for this node. | |
*/ | |
public Expression generateExpression(GenerationContext context) { | |
Expression whereClause = getLeft().generateExpression(context).nullIf(getRight().generateExpression(context)); | |
return whereClause; | |
} | |
public void validate(ParseTreeContext context) { | |
left.validate(context); | |
right.validate(context); | |
setType(left.getType()); | |
} | |
public boolean isAliasableNode(){ | |
return true; | |
} | |
} |