/*******************************************************************************
* Copyright (c) 1998, 2009 Oracle. 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 java.util.Set;
import org.eclipse.persistence.expressions.*;
import org.eclipse.persistence.queries.ReportQuery;
/**
* INTERNAL
* <p><b>Purpose</b>: Represent a subquery.
*/
public class SubqueryNode extends Node {
private JPQLParseTree subqueryParseTree;
/** Set of names of variables declared in an outer scope and used in teh
* subquery. */
private Set outerVars;
/**
* Return a new SubqueryNode.
*/
public SubqueryNode() {
super();
}
/** */
public ReportQuery getReportQuery(GenerationContext context) {
ReportQuery innerQuery = new ReportQuery();
GenerationContext innerContext =
subqueryParseTree.populateSubquery(innerQuery, context);
Expression joins = innerContext.joinVariables(outerVars);
if (joins != null) {
Expression where = innerQuery.getSelectionCriteria();
where = appendExpression(where, joins);
innerQuery.setSelectionCriteria(where);
}
return innerQuery;
}
/**
* INTERNAL
* If called the subquery is part of the WHERE clause of an UPDATE or
* DELETE statement that does not define an identification variable.
* The method checks the clauses of the subquery for unqualified fields
* accesses.
*/
public Node qualifyAttributeAccess(ParseTreeContext context) {
subqueryParseTree.getFromNode().qualifyAttributeAccess(context);
subqueryParseTree.getQueryNode().qualifyAttributeAccess(context);
if (subqueryParseTree.getWhereNode() != null) {
subqueryParseTree.getWhereNode().qualifyAttributeAccess(context);
}
if (subqueryParseTree.getGroupByNode() != null) {
subqueryParseTree.getGroupByNode().qualifyAttributeAccess(context);
}
if (subqueryParseTree.getHavingNode() != null) {
subqueryParseTree.getHavingNode().qualifyAttributeAccess(context);
}
return this;
}
/**
* INTERNAL
* Validate node and calculate its type.
*/
public void validate(ParseTreeContext context) {
subqueryParseTree.validate(context);
outerVars = context.getOuterScopeVariables();
SelectNode selectNode = (SelectNode)subqueryParseTree.getQueryNode();
// Get the select expression, subqueries only have one
Node selectExpr = (Node)selectNode.getSelectExpressions().get(0);
setType(selectExpr.getType());
}
/**
* INTERNAL
* Generate the EclipseLink expression for this node
*/
public Expression generateExpression(GenerationContext context) {
Expression base = context.getBaseExpression();
ReportQuery innerQuery = getReportQuery(context);
return base.subQuery(innerQuery);
}
/**
* INTERNAL
* Is this node a SubqueryNode
*/
public boolean isSubqueryNode() {
return true;
}
/** */
public void setParseTree(JPQLParseTree parseTree) {
this.subqueryParseTree = parseTree;
}
/** */
public JPQLParseTree getParseTree() {
return subqueryParseTree;
}
}