org.eclipse.persistence.internal.jpa.jpql.RangeDeclaration Maven / Gradle / Ivy
Show all versions of org.eclipse.persistence.core Show documentation
/*
* Copyright (c) 2006, 2018 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 v. 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0,
* or the Eclipse Distribution License v. 1.0 which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
*/
// Contributors:
// Oracle - initial API and implementation
//
package org.eclipse.persistence.internal.jpa.jpql;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
import org.eclipse.persistence.descriptors.ClassDescriptor;
import org.eclipse.persistence.expressions.Expression;
import org.eclipse.persistence.expressions.ExpressionBuilder;
import org.eclipse.persistence.jpa.jpql.parser.Join;
import org.eclipse.persistence.mappings.DatabaseMapping;
/**
* This RangeDeclaration represents an identification variable declaration that was
* declared in the FROM clause of a SELECT top-level query
* or subquery.
*
* @see org.eclipse.persistence.jpa.jpql.parser.IdentificationVariableDeclaration IdentificationVariableDeclaration
*
* @version 2.5
* @since 2.4
* @author Pascal Filion
*/
final class RangeDeclaration extends AbstractRangeDeclaration {
/**
* The list of JOIN FETCH expressions that are declared in the same declaration than
* the range variable declaration.
*/
private List joinFetches;
/**
* If the "root" path is the fully qualified class name, then this will be set.
*/
public Class type;
/**
* Creates a new RangeDeclaration.
*
* @param queryContext The context used to query information about the application metadata and
* cached information
*/
RangeDeclaration(JPQLQueryContext queryContext) {
super(queryContext);
}
/**
* {@inheritDoc}
*/
@Override
void addJoin(Join join) {
super.addJoin(join);
if (join.hasFetch()) {
addJoinFetch(join);
}
}
private void addJoinFetch(Join join) {
if (joinFetches == null) {
joinFetches = new LinkedList();
}
joinFetches.add(join);
}
/**
* {@inheritDoc}
*/
@Override
Expression buildQueryExpression() {
ClassDescriptor descriptor = getDescriptor();
// The abstract schema name can't be resolved, we'll assume it's actually an unqualified
// state field path expression or collection-valued path expression declared in an UPDATE
// or DELETE query
if (descriptor == null) {
// Convert the AbstractSchemaName into a CollectionValuedPathExpression since
// it's an unqualified state field path expression or collection-valued path expression
convertUnqualifiedDeclaration();
// The abstract schema name is now a CollectionValuedPathExpression, request the context
// to return the Expression for the new Declaration
return queryContext.getBaseExpression();
}
return new ExpressionBuilder(descriptor.getJavaClass());
}
/**
* Converts the given {@link Declaration} from being set as a range variable declaration to
* a path expression declaration.
*
* In this query "UPDATE Employee SET firstName = 'MODIFIED' WHERE (SELECT COUNT(m) FROM
* managedEmployees m) > 0" managedEmployees is an unqualified collection-valued
* path expression (employee.managedEmployees).
*/
private void convertUnqualifiedDeclaration() {
// Retrieve the range identification variable from the parent declaration
Declaration parentDeclaration = queryContext.getParent().getFirstDeclarationImp();
String outerVariableName = parentDeclaration.getVariableName();
// Qualify the range expression to be fully qualified
queryContext.getDeclarationResolver().convertUnqualifiedDeclaration(this, outerVariableName);
}
/**
* Returns the JOIN FETCH expressions that were part of the range variable declaration
* in the ordered they were parsed.
*
* @return The ordered list of JOIN FETCH expressions or an empty collection if none
* was present
*/
List getJoinFetches() {
return (joinFetches == null) ? Collections.emptyList() : joinFetches;
}
/**
* {@inheritDoc}
*/
@Override
public Type getType() {
return (type != null) ? Type.CLASS_NAME : Type.RANGE;
}
/**
* Determines whether the "root" path is either the abstract schema name (entity name) or the
* abstract schema name.
*
* @return true if it is the fully qualified class name; false if it
* is the entity name
*/
public boolean isFullyQualifiedClassName() {
return type != null;
}
/**
* {@inheritDoc}
*/
@Override
ClassDescriptor resolveDescriptor() {
if (type != null) {
return queryContext.getDescriptor(type);
}
return queryContext.getDescriptor(rootPath);
}
/**
* {@inheritDoc}
*/
@Override
DatabaseMapping resolveMapping() {
// A range declaration does not have a mapping, only a descriptor
return null;
}
}