| /* |
| * Copyright (c) 2012, 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.List; |
| import org.eclipse.persistence.jpa.jpql.ExpressionTools; |
| import org.eclipse.persistence.jpa.jpql.WordParser; |
| |
| /** |
| * The <b>EXTRACT</b> function extracts a date part from a date/time value. The date part can be |
| * <code>YEAR</code>, <code>MONTH</code>, <code>DAY</code>, <code>HOUR</code>, <code>MINUTE</code>, |
| * <code>SECOND</code>. Some databases may support other parts. |
| * |
| * <div><b>BNF:</b> <code>extract_expression ::= EXTRACT(date_part_literal [FROM] scalar_expression)</code></div> |
| * <p> |
| * date_part_literal ::= { MICROSECOND | SECOND | MINUTE | HOUR | DAY | WEEK | MONTH | QUARTER | |
| * YEAR | SECOND_MICROSECOND | MINUTE_MICROSECOND | MINUTE_SECOND | |
| * HOUR_MICROSECOND | HOUR_SECOND | HOUR_MINUTE | DAY_MICROSECOND | |
| * DAY_SECOND | DAY_MINUTE | DAY_HOUR | YEAR_MONTH, etc } |
| * </p> |
| * |
| * @version 2.5 |
| * @since 2.4 |
| * @author James Sutherland |
| */ |
| public final class ExtractExpression extends AbstractSingleEncapsulatedExpression { |
| |
| /** |
| * The date part to extract from the date/time. |
| */ |
| private String datePart; |
| |
| /** |
| * The actual <b>FROM</b> identifier found in the string representation of the JPQL query. |
| */ |
| private String fromIdentifier; |
| |
| /** |
| * Determines whether a space was parsed after the date part. |
| */ |
| private boolean hasSpaceAfterDatePart; |
| |
| /** |
| * Determines whether a space was parsed after the identifier <b>FROM</b>. |
| */ |
| private boolean hasSpaceAfterFrom; |
| |
| /** |
| * Creates a new <code>ExtractExpression</code>. |
| * |
| * @param parent The parent of this expression |
| */ |
| public ExtractExpression(AbstractExpression parent) { |
| super(parent, EXTRACT); |
| } |
| |
| @Override |
| public void accept(ExpressionVisitor visitor) { |
| acceptUnknownVisitor(visitor); |
| } |
| |
| @Override |
| protected void addOrderedEncapsulatedExpressionTo(List<Expression> children) { |
| |
| // Date part |
| if (hasDatePart()) { |
| children.add(buildStringExpression(datePart)); |
| } |
| |
| if (hasSpaceAfterDatePart) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // 'FROM' |
| if (fromIdentifier != null) { |
| children.add(buildStringExpression(FROM)); |
| } |
| |
| if (hasSpaceAfterFrom) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // Value |
| super.addOrderedEncapsulatedExpressionTo(children); |
| } |
| |
| @Override |
| public String getEncapsulatedExpressionQueryBNFId() { |
| return ScalarExpressionBNF.ID; |
| } |
| |
| /** |
| * 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; |
| } |
| |
| /** |
| * Returns the date part that was parsed, it is used to extract a single part of a date/time, |
| * such as year, month, day, your, etc. |
| * |
| * @return The part of the date/time to retrieve |
| */ |
| public String getDatePart() { |
| return datePart; |
| } |
| |
| @Override |
| public JPQLQueryBNF getQueryBNF() { |
| return getQueryBNF(ExtractExpressionBNF.ID); |
| } |
| |
| /** |
| * Determines whether the date part literal was parsed or not. |
| * |
| * @return <code>true</code> if the date part literal was parsed; <code>false</code> otherwise |
| */ |
| public boolean hasDatePart() { |
| return ExpressionTools.stringIsNotEmpty(datePart); |
| } |
| |
| @Override |
| public boolean hasEncapsulatedExpression() { |
| return hasDatePart() || (fromIdentifier != null) || hasExpression(); |
| } |
| |
| /** |
| * Determines whether the identifier <b>FROM</b> was part of the query. |
| * |
| * @return <code>true</code> if the identifier <b>FROM</b> was parsed; <code>false</code> otherwise |
| */ |
| public boolean hasFrom() { |
| return fromIdentifier != null; |
| } |
| |
| /** |
| * Determines whether a whitespace was found after the date part literal. |
| * |
| * @return <code>true</code> if there was a whitespace after the date part literal; |
| * <code>false</code> otherwise |
| */ |
| public boolean hasSpaceAfterDatePart() { |
| return hasSpaceAfterDatePart; |
| } |
| |
| /** |
| * Determines whether a whitespace was found after <b>FROM</b>. |
| * |
| * @return <code>true</code> if there was a whitespace after <b>FROM</b>; <code>false</code> otherwise |
| */ |
| public boolean hasSpaceAfterFrom() { |
| return hasSpaceAfterFrom; |
| } |
| |
| @Override |
| protected boolean isParsingComplete(WordParser wordParser, String word, Expression expression) { |
| return word.equalsIgnoreCase(FROM) || |
| super.isParsingComplete(wordParser, word, expression); |
| } |
| |
| @Override |
| protected void parseEncapsulatedExpression(WordParser wordParser, |
| int whitespaceCount, |
| boolean tolerant) { |
| |
| if (wordParser.isTail()) { |
| datePart = ExpressionTools.EMPTY_STRING; |
| return; |
| } |
| |
| // Parse the date part |
| datePart = wordParser.word(); |
| |
| // Invalid date part, parse it as the scalar expression |
| if (tolerant && |
| (isParsingComplete(wordParser, datePart, null) || |
| datePart.indexOf(DOT) > -1 || |
| datePart.charAt(0) == SINGLE_QUOTE || |
| datePart.charAt(0) == DOUBLE_QUOTE || |
| Character.isDigit(datePart.charAt(0)))) { |
| |
| datePart = ExpressionTools.EMPTY_STRING; |
| hasSpaceAfterDatePart = whitespaceCount > 0; |
| } |
| else { |
| wordParser.moveForward(datePart); |
| hasSpaceAfterDatePart = wordParser.skipLeadingWhitespace() > 0; |
| } |
| |
| // Parse 'FROM' |
| if (wordParser.startsWithIdentifier(FROM)) { |
| fromIdentifier = wordParser.moveForward(FROM); |
| hasSpaceAfterFrom = wordParser.skipLeadingWhitespace() > 0; |
| } |
| |
| // Parse the value |
| super.parseEncapsulatedExpression(wordParser, whitespaceCount, tolerant); |
| } |
| |
| @Override |
| protected void removeEncapsulatedExpression() { |
| super.removeEncapsulatedExpression(); |
| datePart = ExpressionTools.EMPTY_STRING; |
| fromIdentifier = null; |
| hasSpaceAfterFrom = false; |
| hasSpaceAfterDatePart = false; |
| } |
| |
| @Override |
| protected void toParsedTextEncapsulatedExpression(StringBuilder writer, boolean actual) { |
| |
| // Date part |
| writer.append(datePart); |
| |
| if (hasSpaceAfterDatePart) { |
| writer.append(SPACE); |
| } |
| |
| // FROM |
| if (fromIdentifier != null) { |
| writer.append(actual ? fromIdentifier : FROM); |
| } |
| |
| if (hasSpaceAfterFrom) { |
| writer.append(SPACE); |
| } |
| |
| // Value |
| super.toParsedTextEncapsulatedExpression(writer, actual); |
| } |
| } |