| /* |
| * 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.ExpressionTools; |
| import org.eclipse.persistence.jpa.jpql.WordParser; |
| |
| /** |
| * Range variable declarations allow the developer to designate a "root" for objects which may not |
| * be reachable by navigation. In order to select values by comparing more than one instance of an |
| * entity abstract schema type, more than one identification variable ranging over the abstract |
| * schema type is needed in the <b>FROM</b> clause. |
| * <p> |
| * JPA: |
| * <div><b>BNF:</b> <code>range_variable_declaration ::= abstract_schema_name [AS] identification_variable</code></div> |
| * <p> |
| * EclipseLink 2.4: |
| * <div><b>BNF:</b> <code>range_variable_declaration ::= { root_object } [AS] identification_variable</code></div> |
| * |
| * <div><b>BNF:</b> <code>root_object ::= abstract_schema_name | (subquery)</code></div> |
| * |
| * @version 2.5 |
| * @since 2.3 |
| * @author Pascal Filion |
| */ |
| public final class RangeVariableDeclaration extends AbstractExpression { |
| |
| /** |
| * The actual <b>AS</b> identifier found in the string representation of the JPQL query. |
| */ |
| private String asIdentifier; |
| |
| /** |
| * Determines whether a whitespace was parsed after <b>AS</b>. |
| */ |
| private boolean hasSpaceAfterAs; |
| |
| /** |
| * Determines whether a whitespace was parsed after the "root" object. |
| */ |
| private boolean hasSpaceAfterRootObject; |
| |
| /** |
| * The {@link Expression} representing the identification variable. |
| */ |
| private AbstractExpression identificationVariable; |
| |
| /** |
| * The {@link Expression} representing the "root" object. |
| */ |
| private AbstractExpression rootObject; |
| |
| /** |
| * Determines whether the identification variable is virtual, meaning it's not part of the query |
| * but is required for proper navigability. |
| */ |
| private boolean virtualIdentificationVariable; |
| |
| /** |
| * Creates a new <code>RangeVariableDeclaration</code>. |
| * |
| * @param parent The parent of this expression |
| */ |
| public RangeVariableDeclaration(AbstractExpression parent) { |
| super(parent); |
| } |
| |
| /** |
| * Creates a new <code>RangeVariableDeclaration</code>, which is used as a virtual declaration. |
| * |
| * @param entityName The name of the entity to be accessible with the given variable name |
| * @param variableName The identification variable used to navigate to the entity |
| */ |
| public RangeVariableDeclaration(String entityName, String variableName) { |
| super(null); |
| rootObject = new AbstractSchemaName(this, entityName); |
| identificationVariable = new IdentificationVariable(this, variableName); |
| } |
| |
| @Override |
| public void accept(ExpressionVisitor visitor) { |
| visitor.visit(this); |
| } |
| |
| @Override |
| public void acceptChildren(ExpressionVisitor visitor) { |
| getRootObject().accept(visitor); |
| getIdentificationVariable().accept(visitor); |
| } |
| |
| @Override |
| protected void addChildrenTo(Collection<Expression> children) { |
| children.add(getRootObject()); |
| children.add(getIdentificationVariable()); |
| } |
| |
| @Override |
| protected void addOrderedChildrenTo(List<Expression> children) { |
| |
| // "Root" object |
| if (rootObject != null) { |
| children.add(rootObject); |
| } |
| |
| // Space |
| if (hasSpaceAfterRootObject) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // 'AS' |
| if (asIdentifier != null) { |
| children.add(buildStringExpression(AS)); |
| } |
| |
| if (hasSpaceAfterAs) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // Identification variable |
| if (identificationVariable != null) { |
| children.add(identificationVariable); |
| } |
| } |
| |
| @Override |
| public JPQLQueryBNF findQueryBNF(Expression expression) { |
| |
| if ((rootObject != null) && rootObject.isAncestor(expression)) { |
| return getQueryBNF(RangeDeclarationBNF.ID); |
| } |
| |
| if ((identificationVariable != null) && identificationVariable.isAncestor(expression)) { |
| return getQueryBNF(IdentificationVariableBNF.ID); |
| } |
| |
| return super.findQueryBNF(expression); |
| } |
| |
| /** |
| * Returns the actual <b>AS</b> found in the string representation of the JPQL query, which has |
| * the actual case that was used. |
| * |
| * @return The <b>AS</b> identifier that was actually parsed, or an empty string if it was not |
| * parsed |
| */ |
| public String getActualAsIdentifier() { |
| return (asIdentifier != null) ? asIdentifier : ExpressionTools.EMPTY_STRING; |
| } |
| |
| /** |
| * Returns the {@link Expression} that represents the identification variable. |
| * |
| * @return The expression that was parsed representing the identification variable |
| */ |
| public Expression getIdentificationVariable() { |
| if (identificationVariable == null) { |
| identificationVariable = buildNullExpression(); |
| } |
| return identificationVariable; |
| } |
| |
| @Override |
| public JPQLQueryBNF getQueryBNF() { |
| return getQueryBNF(RangeVariableDeclarationBNF.ID); |
| } |
| |
| /** |
| * Returns the {@link Expression} that represents the "root" object. |
| * |
| * @return The expression that was parsed representing the "root" object |
| */ |
| public Expression getRootObject() { |
| if (rootObject == null) { |
| rootObject = buildNullExpression(); |
| } |
| return rootObject; |
| } |
| |
| /** |
| * Determines whether the identifier <b>AS</b> was parsed. |
| * |
| * @return <code>true</code> if the identifier <b>AS</b> was parsed; <code>false</code> otherwise |
| */ |
| public boolean hasAs() { |
| return asIdentifier != null; |
| } |
| |
| /** |
| * Determines whether the identification variable was parsed. |
| * |
| * @return <code>true</code> if the identification variable was parsed; <code>false</code> otherwise |
| */ |
| public boolean hasIdentificationVariable() { |
| return identificationVariable != null && |
| !identificationVariable.isNull() && |
| !identificationVariable.isVirtual(); |
| } |
| |
| /** |
| * Determines whether the "root" object was parsed. |
| * |
| * @return <code>true</code> if the "root" object was parsed; <code>false</code> otherwise |
| */ |
| public boolean hasRootObject() { |
| return rootObject != null && |
| !rootObject.isNull(); |
| } |
| |
| /** |
| * Determines whether a whitespace was parsed after <b>AS</b>. |
| * |
| * @return <code>true</code> if there was a whitespace after <b>AS</b>; <code>false</code> otherwise |
| */ |
| public boolean hasSpaceAfterAs() { |
| return hasSpaceAfterAs; |
| } |
| |
| /** |
| * Determines whether a whitespace was parsed after the "root" object. |
| * |
| * @return <code>true</code> if there was a whitespace after "root" object; |
| * <code>false</code> otherwise |
| */ |
| public boolean hasSpaceAfterRootObject() { |
| return hasSpaceAfterRootObject; |
| } |
| |
| /** |
| * Determines whether this identification variable is virtual, meaning it's not part of the |
| * query but is required for proper navigability. |
| * |
| * @return <code>true</code> if this identification variable was virtually created to fully |
| * qualify path expression; <code>false</code> if it was parsed |
| */ |
| public boolean hasVirtualIdentificationVariable() { |
| return virtualIdentificationVariable; |
| } |
| |
| @Override |
| protected boolean isParsingComplete(WordParser wordParser, String word, Expression expression) { |
| return word.equalsIgnoreCase(AS) || |
| word.equalsIgnoreCase(SET) || |
| word.equalsIgnoreCase(INNER) || |
| word.equalsIgnoreCase(JOIN) || |
| word.equalsIgnoreCase(LEFT) || |
| super.isParsingComplete(wordParser, word, expression); |
| } |
| |
| @Override |
| protected void parse(WordParser wordParser, boolean tolerant) { |
| |
| // Parse the "root" object |
| rootObject = parse(wordParser, RangeDeclarationBNF.ID, tolerant); |
| |
| hasSpaceAfterRootObject = wordParser.skipLeadingWhitespace() > 0; |
| |
| // Parse 'AS' |
| if (wordParser.startsWithIdentifier(AS)) { |
| asIdentifier = wordParser.moveForward(AS); |
| hasSpaceAfterAs = wordParser.skipLeadingWhitespace() > 0; |
| } |
| |
| // Special case when parsing the range variable declaration of an UPDATE clause that does |
| // not have an identification variable, e.g. "UPDATE DateTime SET date = CURRENT_DATE" |
| if (!wordParser.startsWithIdentifier(SET)) { |
| if (tolerant) { |
| identificationVariable = parse(wordParser, IdentificationVariableBNF.ID, tolerant); |
| } |
| else { |
| identificationVariable = new IdentificationVariable(this, wordParser.word()); |
| identificationVariable.parse(wordParser, tolerant); |
| } |
| } |
| } |
| |
| /** |
| * Sets a virtual identification variable because the "root" object was parsed without one. This |
| * is valid in an <b>UPDATE</b> and <b>DELETE</b> queries. Example: |
| * <p> |
| * <code>UPDATE DateTime SET date = CURRENT_DATE</code> |
| * <p> |
| * is equivalent to |
| * <p> |
| * <code>UPDATE DateTime d SET d.date = CURRENT_DATE</code> |
| * |
| * @param variableName A virtual identification variable that will identify the "root" object |
| */ |
| public void setVirtualIdentificationVariable(String variableName) { |
| virtualIdentificationVariable = true; |
| identificationVariable = new IdentificationVariable(this, variableName, true); |
| } |
| |
| /** |
| * Sets a virtual identification variable to qualify the "root" object. The "root" object is a |
| * derived path that does not start with an identification variable. Example: |
| * <p> |
| * <code>UPDATE Employee SET firstName = 'MODIFIED' |
| * WHERE (SELECT COUNT(m) FROM managedEmployees m) {@literal >} 0</code> |
| * <p> |
| * <i>'managedEmployees'</i> is a derived path and will become qualified with the given virtual |
| * identification variable. |
| * |
| * @param variableName The identification variable that was generated to qualify the "root" object |
| * @param path The path that was parsed as a "root" object |
| */ |
| public void setVirtualIdentificationVariable(String variableName, String path) { |
| CollectionValuedPathExpression expression = new CollectionValuedPathExpression(this, path); |
| expression.setVirtualIdentificationVariable(variableName); |
| rootObject = expression; |
| } |
| |
| @Override |
| protected boolean shouldParseWithFactoryFirst() { |
| return false; |
| } |
| |
| @Override |
| protected void toParsedText(StringBuilder writer, boolean actual) { |
| |
| // "Root" object |
| if (rootObject != null) { |
| rootObject.toParsedText(writer, actual); |
| } |
| |
| if (hasSpaceAfterRootObject) { |
| writer.append(SPACE); |
| } |
| |
| // 'AS' |
| if (asIdentifier != null) { |
| writer.append(actual ? asIdentifier : AS); |
| } |
| |
| if (hasSpaceAfterAs) { |
| writer.append(SPACE); |
| } |
| |
| // Identification variable |
| if ((identificationVariable != null) && !virtualIdentificationVariable) { |
| identificationVariable.toParsedText(writer, actual); |
| } |
| } |
| } |