| /* |
| * 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; |
| |
| /** |
| * A query is an operation that retrieves data from one or more tables or views. In this reference, |
| * a top-level <code><b>SELECT</b></code> statement is called a query, and a query nested within |
| * another SQL statement is called a subquery. |
| * |
| * @see SelectStatement |
| * @see SimpleSelectStatement |
| * |
| * @version 2.5 |
| * @since 2.3 |
| * @author Pascal Filion |
| */ |
| public abstract class AbstractSelectStatement extends AbstractExpression { |
| |
| /** |
| * The <code><b>FROM</b></code> clause of this select statement. |
| */ |
| private AbstractExpression fromClause; |
| |
| /** |
| * The <code><b>GROUP BY</b></code> clause of this select statement. |
| */ |
| private AbstractExpression groupByClause; |
| |
| /** |
| * Determines whether there is a whitespace after the identifier <code><b>FROM</b></code>. |
| */ |
| private boolean hasSpaceAfterFrom; |
| |
| /** |
| * Determines whether there is a whitespace after the identifier <code><b>GROUP BY</b></code>. |
| */ |
| private boolean hasSpaceAfterGroupBy; |
| |
| /** |
| * Determines whether there is a whitespace after the identifier <code><b>SELECT</b></code>. |
| */ |
| private boolean hasSpaceAfterSelect; |
| |
| /** |
| * Determines whether there is a whitespace after the identifier <code><b>WHERE</b></code>. |
| */ |
| private boolean hasSpaceAfterWhere; |
| |
| /** |
| * The <code><b>HAVING</b></code> clause of this select statement. |
| */ |
| private AbstractExpression havingClause; |
| |
| /** |
| * The <code><b>SELECT</b></code> clause of this select statement. |
| */ |
| private AbstractExpression selectClause; |
| |
| /** |
| * The <code><b>WHERE</b></code> clause of this select statement. |
| */ |
| private AbstractExpression whereClause; |
| |
| /** |
| * Creates a new <code>AbstractSelectStatement</code>. |
| * |
| * @param parent The parent of this expression |
| */ |
| protected AbstractSelectStatement(AbstractExpression parent) { |
| super(parent); |
| } |
| |
| @Override |
| public void acceptChildren(ExpressionVisitor visitor) { |
| getSelectClause().accept(visitor); |
| getFromClause().accept(visitor); |
| getWhereClause().accept(visitor); |
| getGroupByClause().accept(visitor); |
| getHavingClause().accept(visitor); |
| } |
| |
| @Override |
| protected void addChildrenTo(Collection<Expression> children) { |
| children.add(getSelectClause()); |
| children.add(getFromClause()); |
| children.add(getWhereClause()); |
| children.add(getGroupByClause()); |
| children.add(getHavingClause()); |
| } |
| |
| @Override |
| protected void addOrderedChildrenTo(List<Expression> children) { |
| |
| // SELECT clause |
| if (selectClause != null) { |
| children.add(selectClause); |
| } |
| |
| // Space between SELECT and FROM clauses |
| if (hasSpaceAfterSelect) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // FROM clause |
| if (fromClause != null) { |
| children.add(fromClause); |
| } |
| |
| // Space between the FROM clause and an optional clause |
| if (hasSpaceAfterFrom) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // WHERE clause |
| if (whereClause != null) { |
| children.add(whereClause); |
| } |
| |
| // Space between WHERE clause and another optional clause |
| if (hasSpaceAfterWhere) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // GROUP BY clause |
| if (groupByClause != null) { |
| children.add(groupByClause); |
| } |
| |
| // Space between GROUP BY clause and another optional clause |
| if (hasSpaceAfterGroupBy) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| // HAVING clause |
| if (havingClause != null) { |
| children.add(havingClause); |
| } |
| } |
| |
| /** |
| * Creates the expression representing the from clause of this select statement. |
| * |
| * @return A new from clause, <code>null</code> can't be returned |
| */ |
| protected abstract AbstractFromClause buildFromClause(); |
| |
| /** |
| * Creates the expression representing the select clause of this select statement. |
| * |
| * @return A new from clause, <code>null</code> can't be returned |
| */ |
| protected abstract AbstractSelectClause buildSelectClause(); |
| |
| @Override |
| public JPQLQueryBNF findQueryBNF(Expression expression) { |
| |
| if ((selectClause != null) && selectClause.isAncestor(expression)) { |
| return selectClause.getQueryBNF(); |
| } |
| |
| if ((fromClause != null) && fromClause.isAncestor(expression)) { |
| return fromClause.getQueryBNF(); |
| } |
| |
| if ((whereClause != null) && whereClause.isAncestor(expression)) { |
| return whereClause.getQueryBNF(); |
| } |
| |
| if ((groupByClause != null) && groupByClause.isAncestor(expression)) { |
| return groupByClause.getQueryBNF(); |
| } |
| |
| if ((havingClause != null) && havingClause.isAncestor(expression)) { |
| return havingClause.getQueryBNF(); |
| } |
| |
| return super.findQueryBNF(expression); |
| } |
| |
| /** |
| * Returns the {@link Expression} representing the <b>FROM</b> clause. |
| * |
| * @return The expression representing the <b>FROM</b> clause |
| */ |
| public final Expression getFromClause() { |
| if (fromClause == null) { |
| fromClause = buildNullExpression(); |
| } |
| return fromClause; |
| } |
| |
| /** |
| * Returns the {@link Expression} representing the <b>GROUP BY</b> clause. |
| * |
| * @return The expression representing the <b>GROUP BY</b> clause |
| */ |
| public final Expression getGroupByClause() { |
| if (groupByClause == null) { |
| groupByClause = buildNullExpression(); |
| } |
| return groupByClause; |
| } |
| |
| /** |
| * Returns the {@link Expression} representing the <b>HAVING</b> clause. |
| * |
| * @return The expression representing the <b>HAVING</b> clause |
| */ |
| public final Expression getHavingClause() { |
| if (havingClause == null) { |
| havingClause = buildNullExpression(); |
| } |
| return havingClause; |
| } |
| |
| /** |
| * Returns the {@link AbstractSelectClause} representing the <b>SELECT</b> clause. |
| * |
| * @return The expression representing the <b>SELECT</b> clause |
| */ |
| public final Expression getSelectClause() { |
| if (selectClause == null) { |
| selectClause = buildNullExpression(); |
| } |
| return selectClause; |
| } |
| |
| /** |
| * Returns the {@link Expression} representing the <b>WHERE</b> clause. |
| * |
| * @return The expression representing the <b>WHERE</b> clause |
| */ |
| public final Expression getWhereClause() { |
| if (whereClause == null) { |
| whereClause = buildNullExpression(); |
| } |
| return whereClause; |
| } |
| |
| /** |
| * Determines whether the <b>FROM</b> clause was parsed or not. |
| * |
| * @return <code>true</code> if the query that got parsed had the <b>FROM</b> clause |
| */ |
| public final boolean hasFromClause() { |
| return fromClause != null && |
| !fromClause.isNull(); |
| } |
| |
| /** |
| * Determines whether the <b>GROUP BY</b> clause was parsed or not. |
| * |
| * @return <code>true</code> if the query that got parsed had the <b>GROUP BY</b> clause |
| */ |
| public final boolean hasGroupByClause() { |
| return groupByClause != null && |
| !groupByClause.isNull(); |
| } |
| |
| /** |
| * Determines whether the <b>HAVING</b> clause was parsed or not. |
| * |
| * @return <code>true</code> if the query that got parsed had the <b>HAVING</b> clause |
| */ |
| public final boolean hasHavingClause() { |
| return havingClause != null && |
| !havingClause.isNull(); |
| } |
| |
| /** |
| * Determines whether the <b>SELECT</b> clause was parsed or not. |
| * |
| * @return <code>true</code> if the query that got parsed had the <b>HAVING</b> clause |
| * @since 2.5 |
| */ |
| public final boolean hasSelectClause() { |
| return selectClause != null && |
| !selectClause.isNull(); |
| } |
| |
| /** |
| * Determines whether a whitespace was found after the <b>FROM</b> clause. In some cases, the |
| * space is owned by a child of the <b>FROM</b> clause. |
| * |
| * @return <code>true</code> if there was a whitespace after the <b>FROM</b> clause and owned by |
| * this expression; <code>false</code> otherwise |
| */ |
| public final boolean hasSpaceAfterFrom() { |
| return hasSpaceAfterFrom; |
| } |
| |
| /** |
| * Determines whether a whitespace was found after the <b>GROUP BY</b> clause. In some cases, the |
| * space is owned by a child of the <b>GROUP BY</b> clause. |
| * |
| * @return <code>true</code> if there was a whitespace after the <b>GROUP BY</b> clause and owned |
| * by this expression; <code>false</code> otherwise |
| */ |
| public final boolean hasSpaceAfterGroupBy() { |
| return hasSpaceAfterGroupBy; |
| } |
| |
| /** |
| * Determines whether a whitespace was found after the <b>SELECT</b> clause. In some cases, the |
| * space is owned by a child of the <b>SELECT</b> clause. |
| * |
| * @return <code>true</code> if there was a whitespace after the <b>SELECT</b> clause and owned |
| * by this expression; <code>false</code> otherwise |
| */ |
| public final boolean hasSpaceAfterSelect() { |
| return hasSpaceAfterSelect; |
| } |
| |
| /** |
| * Determines whether a whitespace was found after the <b>WHERE</b> clause. In some cases, the |
| * space is owned by a child of the <b>WHERE</b> clause. |
| * |
| * @return <code>true</code> if there was a whitespace after the <b>WHERE</b> clause and owned by |
| * this expression; <code>false</code> otherwise |
| */ |
| public final boolean hasSpaceAfterWhere() { |
| return hasSpaceAfterWhere; |
| } |
| |
| /** |
| * 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 final boolean hasWhereClause() { |
| return whereClause != null && |
| !whereClause.isNull(); |
| } |
| |
| @Override |
| protected void parse(WordParser wordParser, boolean tolerant) { |
| |
| // Parse 'SELECT' clause |
| if (wordParser.startsWithIdentifier(SELECT)) { |
| selectClause = buildSelectClause(); |
| selectClause.parse(wordParser, tolerant); |
| |
| hasSpaceAfterSelect = wordParser.skipLeadingWhitespace() > 0; |
| } |
| |
| // Parse 'FROM' clause |
| if (wordParser.startsWithIdentifier(FROM)) { |
| fromClause = buildFromClause(); |
| fromClause.parse(wordParser, tolerant); |
| |
| hasSpaceAfterFrom = wordParser.skipLeadingWhitespace() > 0; |
| } |
| |
| // Parse 'WHERE' clause |
| if (wordParser.startsWithIdentifier(WHERE)) { |
| whereClause = new WhereClause(this); |
| whereClause.parse(wordParser, tolerant); |
| |
| hasSpaceAfterWhere = wordParser.skipLeadingWhitespace() > 0; |
| } |
| |
| // Parse 'GROUP BY' clause |
| if (wordParser.startsWithIdentifier(GROUP_BY)) { |
| groupByClause = new GroupByClause(this); |
| groupByClause.parse(wordParser, tolerant); |
| |
| hasSpaceAfterGroupBy = wordParser.skipLeadingWhitespace() > 0; |
| } |
| |
| // Parse 'HAVING' clause |
| if (wordParser.startsWithIdentifier(HAVING)) { |
| havingClause = new HavingClause(this); |
| havingClause.parse(wordParser, tolerant); |
| } |
| |
| if (!wordParser.isTail() && !shouldManageSpaceAfterClause()) { |
| |
| if (hasSpaceAfterFrom && |
| whereClause == null && |
| groupByClause == null && |
| havingClause == null) { |
| |
| hasSpaceAfterFrom = false; |
| wordParser.moveBackward(1); |
| } |
| else if (hasSpaceAfterWhere && |
| groupByClause == null && |
| havingClause == null) { |
| |
| hasSpaceAfterWhere = false; |
| wordParser.moveBackward(1); |
| } |
| else if (hasSpaceAfterGroupBy && |
| havingClause == null) { |
| |
| hasSpaceAfterGroupBy = false; |
| wordParser.moveBackward(1); |
| } |
| } |
| } |
| |
| /** |
| * Determines whether the whitespace following the <code><b>HAVING</b></code> clause should be |
| * managed by this expression or not. |
| * |
| * @return <code>true</code> by default to keep the whitespace part of this expression; |
| * <code>false</code> to let the parent handle it |
| */ |
| protected boolean shouldManageSpaceAfterClause() { |
| return true; |
| } |
| |
| @Override |
| protected void toParsedText(StringBuilder writer, boolean actual) { |
| |
| // SELECT clause |
| if (selectClause != null) { |
| selectClause.toParsedText(writer, actual); |
| } |
| |
| if (hasSpaceAfterSelect) { |
| writer.append(SPACE); |
| } |
| |
| // FROM clause |
| if (fromClause != null) { |
| fromClause.toParsedText(writer, actual); |
| } |
| |
| if (hasSpaceAfterFrom) { |
| writer.append(SPACE); |
| } |
| |
| // WHERE clause |
| if (whereClause != null) { |
| whereClause.toParsedText(writer, actual); |
| } |
| |
| if (hasSpaceAfterWhere) { |
| writer.append(SPACE); |
| } |
| |
| // GROUP BY clause |
| if (groupByClause != null) { |
| groupByClause.toParsedText(writer, actual); |
| } |
| |
| if (hasSpaceAfterGroupBy) { |
| writer.append(SPACE); |
| } |
| |
| // HAVING clause |
| if (havingClause != null) { |
| havingClause.toParsedText(writer, actual); |
| } |
| } |
| } |