/*******************************************************************************
* 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;
import org.eclipse.persistence.queries.ObjectLevelReadQuery;
import org.eclipse.persistence.queries.ReportQuery;
import org.eclipse.persistence.expressions.Expression;
/**
* INTERNAL
* <p><b>Purpose</b>: Model a COUNT
* <p><b>Responsibilities</b>:<ul>
* <li> Apply itself to a query correctly
* </ul>
* @author Jon Driscoll
* @since TopLink 5.0
*/
public class CountNode extends AggregateNode {
/**
* INTERNAL
* Apply this node to the passed query
*/
public void applyToQuery(ObjectLevelReadQuery theQuery, GenerationContext context) {
if (theQuery.isReportQuery()) {
ReportQuery reportQuery = (ReportQuery)theQuery;
String attrName = getLeft().isDotNode() ? resolveAttribute() : "COUNT";
reportQuery.addAttribute(attrName, generateExpression(context), Long.class);
}
}
/**
* INTERNAL
* Validate node and calculate its type.
*/
public void validate(ParseTreeContext context) {
if (left != null) {
left.validate(context);
TypeHelper typeHelper = context.getTypeHelper();
setType(typeHelper.getLongClassType());
}
}
/**
* INTERNAL
*/
protected Expression addAggregateExression(Expression expr) {
return expr.count();
}
/**
* INTERNAL
* Is this node a CountNode
*/
public boolean isCountNode() {
return true;
}
/**
* INTERNAL
* Get the string representation of this node.
*/
public String getAsString() {
return "COUNT(" + left.getAsString() + ")";
}
}