| /* |
| * 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; |
| |
| /** |
| * The <b>UPDATE</b> clause of a query consists of a conditional expression used to select objects |
| * or values that satisfy the expression. The <b>UPDATE</b> clause restricts the result of a select |
| * statement or the scope of an update operation. |
| * |
| * <div><b>BNF:</b> <code>update_statement ::= update_clause [where_clause]</code><p></p></div> |
| * |
| * @see JPQLExpression |
| * @see UpdateClause |
| * @see WhereClause |
| * |
| * @version 2.5 |
| * @since 2.3 |
| * @author Pascal Filion |
| */ |
| public final class UpdateStatement extends AbstractExpression { |
| |
| /** |
| * Determines whether a whitespace was parsed after the <b>UPDATE</b> clause. |
| */ |
| private boolean hasSpaceAfterUpdateClause; |
| |
| /** |
| * The expression representing the <b>UPDATE</b> clause. |
| */ |
| private UpdateClause updateClause; |
| |
| /** |
| * The expression representing the <b>WHERE</b> clause. |
| */ |
| private AbstractExpression whereClause; |
| |
| /** |
| * Creates a new <code>UpdateStatement</code>. |
| * |
| * @param parent The parent of this expression |
| */ |
| public UpdateStatement(AbstractExpression parent) { |
| super(parent); |
| } |
| |
| @Override |
| public void accept(ExpressionVisitor visitor) { |
| visitor.visit(this); |
| } |
| |
| @Override |
| public void acceptChildren(ExpressionVisitor visitor) { |
| getUpdateClause().accept(visitor); |
| getWhereClause().accept(visitor); |
| } |
| |
| @Override |
| protected void addChildrenTo(Collection<Expression> children) { |
| children.add(getUpdateClause()); |
| children.add(getWhereClause()); |
| } |
| |
| @Override |
| protected void addOrderedChildrenTo(List<Expression> children) { |
| |
| // Update clause |
| children.add(updateClause); |
| |
| if (hasSpaceAfterUpdateClause) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // Where clause |
| if (whereClause != null) { |
| children.add(whereClause); |
| } |
| } |
| |
| @Override |
| public JPQLQueryBNF findQueryBNF(Expression expression) { |
| |
| if (updateClause.isAncestor(expression)) { |
| return getQueryBNF(UpdateClauseBNF.ID); |
| } |
| |
| if ((whereClause != null) && whereClause.isAncestor(expression)) { |
| return getQueryBNF(WhereClauseBNF.ID); |
| } |
| |
| return super.findQueryBNF(expression); |
| } |
| |
| @Override |
| public JPQLQueryBNF getQueryBNF() { |
| return getQueryBNF(UpdateStatementBNF.ID); |
| } |
| |
| /** |
| * Returns the {@link UpdateClause} representing the <b>UPDATE</b> clause. |
| * |
| * @return The section of the update statement representing the <b>UPDATE</b> clause |
| */ |
| public UpdateClause getUpdateClause() { |
| return updateClause; |
| } |
| |
| /** |
| * Returns the {@link Expression} representing the <b>WHERE</b> clause. |
| * |
| * @return The section of the update statement representing the <b>WHERE</b> clause |
| */ |
| public Expression getWhereClause() { |
| if (whereClause == null) { |
| whereClause = buildNullExpression(); |
| } |
| return whereClause; |
| } |
| |
| /** |
| * Determines whether a whitespace was parsed after the <b>UPDATE</b> clause. |
| * |
| * @return <code>true</code> if a whitespace was parsed after the <b>UPDATE</b> clause; |
| * <code>false</code> otherwise |
| */ |
| public boolean hasSpaceAfterUpdateClause() { |
| return hasSpaceAfterUpdateClause; |
| } |
| |
| /** |
| * Determines whether the <b>WHERE</b> clause is defined or not. |
| * |
| * @return <code>true</code> if this statement has a <b>WHERE</b> clause; <code>false</code> if |
| * it was not parsed |
| */ |
| public boolean hasWhereClause() { |
| return whereClause != null && |
| !whereClause.isNull(); |
| } |
| |
| @Override |
| protected void parse(WordParser wordParser, boolean tolerant) { |
| |
| // Parse 'UPDATE' |
| updateClause = new UpdateClause(this); |
| updateClause.parse(wordParser, tolerant); |
| |
| hasSpaceAfterUpdateClause = 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) { |
| |
| // Update clause |
| updateClause.toParsedText(writer, actual); |
| |
| if (hasSpaceAfterUpdateClause) { |
| writer.append(SPACE); |
| } |
| |
| // Where clause |
| if (whereClause != null) { |
| whereClause.toParsedText(writer, actual); |
| } |
| } |
| } |