| /* |
| * Copyright (c) 2006, 2021 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.jpa.jpql.parser; |
| |
| import java.util.Collection; |
| import java.util.List; |
| import org.eclipse.persistence.jpa.jpql.WordParser; |
| |
| /** |
| * Bulk delete operation apply to entities of a single entity class (together with its subclasses, |
| * if any). |
| * |
| * <div><b>BNF:</b> <code>delete_statement ::= delete_clause [where_clause]</code></div> |
| * |
| * @version 2.5 |
| * @since 2.3 |
| * @author Pascal Filion |
| */ |
| public final class DeleteStatement extends AbstractExpression { |
| |
| /** |
| * The 'DELETE' clause of this expression. |
| */ |
| private DeleteClause deleteClause; |
| |
| /** |
| * Determines whether a whitespace was parsed after the <b>DELETE</b> clause. |
| */ |
| private boolean hasSpace; |
| |
| /** |
| * The optional 'WHERE' clause of this expression. |
| */ |
| private AbstractExpression whereClause; |
| |
| /** |
| * Creates a new <code>DeleteStatement</code>. |
| * |
| * @param parent The parent of this expression |
| */ |
| public DeleteStatement(AbstractExpression parent) { |
| super(parent); |
| } |
| |
| @Override |
| public void accept(ExpressionVisitor visitor) { |
| visitor.visit(this); |
| } |
| |
| @Override |
| public void acceptChildren(ExpressionVisitor visitor) { |
| getDeleteClause().accept(visitor); |
| getWhereClause().accept(visitor); |
| } |
| |
| @Override |
| protected void addChildrenTo(Collection<Expression> children) { |
| children.add(getDeleteClause()); |
| children.add(getWhereClause()); |
| } |
| |
| /** |
| * Manually adds the delete clause to this delete statement. |
| */ |
| public DeleteClause addDeleteClause() { |
| return deleteClause = new DeleteClause(this); |
| } |
| |
| @Override |
| protected void addOrderedChildrenTo(List<Expression> children) { |
| |
| children.add(deleteClause); |
| |
| if (hasSpace) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| children.add(whereClause); |
| } |
| |
| @Override |
| public JPQLQueryBNF findQueryBNF(Expression expression) { |
| |
| if ((deleteClause != null) && deleteClause.isAncestor(expression)) { |
| return getQueryBNF(DeleteClauseBNF.ID); |
| } |
| |
| if ((whereClause != null) && whereClause.isAncestor(expression)) { |
| return getQueryBNF(WhereClauseBNF.ID); |
| } |
| |
| return super.findQueryBNF(expression); |
| } |
| |
| /** |
| * Returns the {@link Expression} representing the <b>DELETE</b> clause. |
| * |
| * @return The expression that was parsed representing the <b>DELETE</b> expression |
| */ |
| public DeleteClause getDeleteClause() { |
| return deleteClause; |
| } |
| |
| @Override |
| public JPQLQueryBNF getQueryBNF() { |
| return getQueryBNF(DeleteStatementBNF.ID); |
| } |
| |
| /** |
| * Returns the {@link Expression} representing the <b>WHERE</b> clause. |
| * |
| * @return The expression representing the <b>WHERE</b> clause |
| */ |
| public Expression getWhereClause() { |
| if (whereClause == null) { |
| whereClause = buildNullExpression(); |
| } |
| return whereClause; |
| } |
| |
| /** |
| * Determines whether a whitespace was found after the <b>DELETE FROM</b> clause. In some cases, |
| * the space is owned by a child of the <b>DELETE FROM</b> clause. |
| * |
| * @return <code>true</code> if there was a whitespace after the <b>DELETE FROM</b> clause and |
| * owned by this expression; <code>false</code> otherwise |
| */ |
| public boolean hasSpaceAfterDeleteClause() { |
| return hasSpace; |
| } |
| |
| /** |
| * Determines whether the <b>WHERE</b> clause is defined. |
| * |
| * @return <code>true</code> if the query that got parsed had the <b>WHERE</b> clause |
| */ |
| public boolean hasWhereClause() { |
| return whereClause != null && |
| !whereClause.isNull(); |
| } |
| |
| @Override |
| protected void parse(WordParser wordParser, boolean tolerant) { |
| |
| // Parse 'DELETE FROM' |
| deleteClause = new DeleteClause(this); |
| deleteClause.parse(wordParser, tolerant); |
| |
| hasSpace = wordParser.skipLeadingWhitespace() > 0; |
| |
| // Parse 'WHERE' |
| if (wordParser.startsWithIdentifier(WHERE)) { |
| whereClause = new WhereClause(this); |
| whereClause.parse(wordParser, tolerant); |
| } |
| |
| // Now fully qualify attribute names with a virtual identification variable |
| accept(new FullyQualifyPathExpressionVisitor()); |
| } |
| |
| @Override |
| protected void toParsedText(StringBuilder writer, boolean actual) { |
| |
| deleteClause.toParsedText(writer, actual); |
| |
| if (hasSpace) { |
| writer.append(SPACE); |
| } |
| |
| if (whereClause != null) { |
| whereClause.toParsedText(writer, actual); |
| } |
| } |
| } |