| /* |
| * Copyright (c) 2011, 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.tools.model.query; |
| |
| import org.eclipse.persistence.jpa.jpql.parser.FromClause; |
| import org.eclipse.persistence.jpa.jpql.parser.InternalFromClauseBNF; |
| import org.eclipse.persistence.jpa.jpql.tools.spi.IManagedType; |
| |
| /** |
| * The <code><b>FROM</b></code> clause of a query defines the domain of the query by declaring |
| * identification variables. An identification variable is an identifier declared in the |
| * <code><b>FROM</b></code> clause of a query. The domain of the query may be constrained by path |
| * expressions. Identification variables designate instances of a particular entity abstract schema |
| * type. The <code><b>FROM</b></code> clause can contain multiple identification variable |
| * declarations separated by a comma (,). |
| * |
| * <pre><code>BNF: from_clause ::= FROM identification_variable_declaration {, {identification_variable_declaration | collection_member_declaration}}*</code></pre> |
| * |
| * @see CollectionMemberDeclarationStateObject |
| * @see IdentificationVariableDeclarationStateObject |
| * @see JoinStateObject |
| * @see SelectStatementStateObject |
| * |
| * @see FromClause |
| * |
| * @version 2.4 |
| * @since 2.4 |
| * @author Pascal Filion |
| */ |
| public class FromClauseStateObject extends AbstractFromClauseStateObject { |
| |
| /** |
| * Creates a new <code>FromClauseStateObject</code>. |
| * |
| * @param parent The parent of this state object, which cannot be <code>null</code> |
| * @exception NullPointerException The given parent cannot be <code>null</code> |
| */ |
| public FromClauseStateObject(SelectStatementStateObject parent) { |
| super(parent); |
| } |
| |
| @Override |
| public void accept(StateObjectVisitor visitor) { |
| visitor.visit(this); |
| } |
| |
| @Override |
| protected String declarationBNF() { |
| return InternalFromClauseBNF.ID; |
| } |
| |
| @Override |
| public IManagedType findManagedType(StateObject stateObject) { |
| // This is the declaration clause of the top-level query |
| return getManagedType(stateObject); |
| } |
| |
| @Override |
| public FromClause getExpression() { |
| return (FromClause) super.getExpression(); |
| } |
| |
| @Override |
| public SelectStatementStateObject getParent() { |
| return (SelectStatementStateObject) super.getParent(); |
| } |
| |
| /** |
| * Keeps a reference of the {@link FromClause parsed object} object, which should only be done |
| * when this object is instantiated during the conversion of a parsed JPQL query into {@link |
| * StateObject StateObjects}. |
| * |
| * @param expression The {@link FromClause parsed object} representing a <code><b>FROM</b></code> |
| * expression |
| */ |
| public void setExpression(FromClause expression) { |
| super.setExpression(expression); |
| } |
| } |