| /* |
| * 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.ArrayList; |
| import java.util.Collection; |
| import java.util.List; |
| import org.eclipse.persistence.jpa.jpql.ExpressionTools; |
| import org.eclipse.persistence.jpa.jpql.WordParser; |
| |
| /** |
| * This is the delete clause of the delete statement. |
| * <p> |
| * A <b>DELETE</b> statement provides bulk operations over sets of entities of a single entity class |
| * (together with its subclasses, if any). Only one entity abstract schema type may be specified in |
| * the <b>UPDATE</b> clause. |
| * |
| * <div><b>BNF:</b> <code>delete_clause ::= DELETE FROM abstract_schema_name [[AS] identification_variable]</code></div> |
| * <p> |
| * Example: <code>DELETE FROM Employee e</code> |
| * |
| * @version 2.5 |
| * @since 2.3 |
| * @author Pascal Filion |
| */ |
| public final class DeleteClause extends AbstractExpression { |
| |
| /** |
| * The actual <b>DELETE</b> identifier found in the string representation of the JPQL query. |
| */ |
| private String deleteIdentifier; |
| |
| /** |
| * The actual <b>FROM</b> identifier found in the string representation of the JPQL query. |
| */ |
| private String fromIdentifier; |
| |
| /** |
| * Determines whether a whitespace was parsed after <b>DELETE</b>. |
| */ |
| private boolean hasSpaceAfterDelete; |
| |
| /** |
| * Determines whether a whitespace was parsed after <b>FROM</b>. |
| */ |
| private boolean hasSpaceAfterFrom; |
| |
| /** |
| * The {@link Expression} representing the range variable declaration. |
| */ |
| private AbstractExpression rangeVariableDeclaration; |
| |
| /** |
| * Creates a new <code>DeleteClause</code>. |
| * |
| * @param parent The parent of this expression |
| */ |
| public DeleteClause(AbstractExpression parent) { |
| super(parent, DELETE); |
| } |
| |
| @Override |
| public void accept(ExpressionVisitor visitor) { |
| visitor.visit(this); |
| } |
| |
| @Override |
| public void acceptChildren(ExpressionVisitor visitor) { |
| getRangeVariableDeclaration().accept(visitor); |
| } |
| |
| @Override |
| protected void addChildrenTo(Collection<Expression> children) { |
| children.add(getRangeVariableDeclaration()); |
| } |
| |
| @Override |
| protected void addOrderedChildrenTo(List<Expression> children) { |
| |
| // 'DELETE' |
| children.add(buildStringExpression(DELETE)); |
| |
| if (hasSpaceAfterDelete) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // 'FROM' |
| if (fromIdentifier != null) { |
| children.add(buildStringExpression(FROM)); |
| } |
| |
| if (hasSpaceAfterFrom) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // Range declaration variable |
| if (rangeVariableDeclaration != null) { |
| children.add(rangeVariableDeclaration); |
| } |
| } |
| |
| /** |
| * Creates a new {@link CollectionExpression} that will wrap the single range variable declaration. |
| * |
| * @return The single range variable declaration represented by a temporary collection |
| */ |
| public CollectionExpression buildCollectionExpression() { |
| |
| List<AbstractExpression> children = new ArrayList<>(1); |
| children.add((AbstractExpression) getRangeVariableDeclaration()); |
| |
| List<Boolean> commas = new ArrayList<>(1); |
| commas.add(Boolean.FALSE); |
| |
| List<Boolean> spaces = new ArrayList<>(1); |
| spaces.add(Boolean.FALSE); |
| |
| return new CollectionExpression(this, children, commas, spaces, true); |
| } |
| |
| @Override |
| public JPQLQueryBNF findQueryBNF(Expression expression) { |
| |
| if ((rangeVariableDeclaration != null) && rangeVariableDeclaration.isAncestor(expression)) { |
| return getQueryBNF(DeleteClauseRangeVariableDeclarationBNF.ID); |
| } |
| |
| return super.findQueryBNF(expression); |
| } |
| |
| /** |
| * Returns the actual <b>DELETE</b> found in the string representation of the JPQL query, which |
| * has the actual case that was used. |
| * |
| * @return The <b>DELETE</b> identifier that was actually parsed, or an empty string if it was |
| * not parsed |
| */ |
| public String getActualDeleteIdentifier() { |
| return (deleteIdentifier != null) ? deleteIdentifier : ExpressionTools.EMPTY_STRING; |
| } |
| |
| /** |
| * Returns the actual <b>FROM</b> identifier found in the string representation of the JPQL |
| * query, which has the actual case that was used. |
| * |
| * @return The <b>FROM</b> identifier that was actually parsed, or an empty string if it was |
| * not parsed |
| */ |
| public String getActualFromIdentifier() { |
| return (fromIdentifier != null) ? fromIdentifier : ExpressionTools.EMPTY_STRING; |
| } |
| |
| @Override |
| public JPQLQueryBNF getQueryBNF() { |
| return getQueryBNF(DeleteClauseBNF.ID); |
| } |
| |
| /** |
| * Returns the {@link Expression} representing the range variable declaration. |
| * |
| * @return The expression representing the range variable declaration |
| */ |
| public Expression getRangeVariableDeclaration() { |
| if (rangeVariableDeclaration == null) { |
| rangeVariableDeclaration = buildNullExpression(); |
| } |
| return rangeVariableDeclaration; |
| } |
| |
| /** |
| * Determines whether the identifier <b>FROM</b> was parsed. |
| * |
| * @return <code>true</code> if <b>FROM</b> was parsed; <code>false</code> otherwise |
| */ |
| public boolean hasFrom() { |
| return fromIdentifier != null; |
| } |
| |
| /** |
| * Determines whether the range variable declaration was parsed. |
| * |
| * @return <code>true</code> if the range variable declaration was parsed; <code>false</code> otherwise |
| */ |
| public boolean hasRangeVariableDeclaration() { |
| return rangeVariableDeclaration != null && |
| !rangeVariableDeclaration.isNull(); |
| } |
| |
| /** |
| * Determines whether a whitespace was found after the identifier <b>DELETE</b>. |
| * |
| * @return <code>true</code> if there was a whitespace after the identifier <b>DELETE</b>; |
| * <code>false</code> otherwise |
| */ |
| public boolean hasSpaceAfterDelete() { |
| return hasSpaceAfterDelete; |
| } |
| |
| /** |
| * Determines whether a whitespace was found after the identifier <b>FROM</b>. |
| * |
| * @return <code>true</code> if there was a whitespace after the identifier <b>FROM</b>; |
| * <code>false</code> otherwise |
| */ |
| public boolean hasSpaceAfterFrom() { |
| return hasSpaceAfterFrom; |
| } |
| |
| @Override |
| protected void parse(WordParser wordParser, boolean tolerant) { |
| |
| // Parse 'DELETE' |
| deleteIdentifier = wordParser.moveForward(DELETE); |
| |
| hasSpaceAfterDelete = wordParser.skipLeadingWhitespace() > 0; |
| |
| // Parse 'FROM' |
| if (!tolerant || wordParser.startsWithIdentifier(FROM)) { |
| fromIdentifier = wordParser.moveForward(FROM); |
| hasSpaceAfterFrom = wordParser.skipLeadingWhitespace() > 0; |
| } |
| |
| // Parse the range variable declaration |
| if (tolerant) { |
| rangeVariableDeclaration = parse( |
| wordParser, |
| DeleteClauseRangeVariableDeclarationBNF.ID, |
| tolerant |
| ); |
| } |
| else { |
| rangeVariableDeclaration = new RangeVariableDeclaration(this); |
| rangeVariableDeclaration.parse(wordParser, tolerant); |
| } |
| } |
| |
| @Override |
| protected void toParsedText(StringBuilder writer, boolean actual) { |
| |
| // 'DELETE' |
| writer.append(actual ? deleteIdentifier : DELETE); |
| |
| if (hasSpaceAfterDelete) { |
| writer.append(SPACE); |
| } |
| |
| // 'FROM' |
| if (fromIdentifier != null) { |
| writer.append(actual ? fromIdentifier : FROM); |
| } |
| |
| if (hasSpaceAfterFrom) { |
| writer.append(SPACE); |
| } |
| |
| // Range variable declaration |
| if (rangeVariableDeclaration != null) { |
| rangeVariableDeclaration.toParsedText(writer, actual); |
| } |
| } |
| } |