| /* |
| * Copyright (c) 1998, 2020 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 from Oracle TopLink |
| package org.eclipse.persistence.queries; |
| |
| /** |
| * <p><b>Purpose</b>: |
| * Concrete class to perform a read of a single data value. |
| * |
| * <p><b>Responsibilities</b>: |
| * Used in conjunction with CursoredStream size and Platform getSequence. |
| * This can be used to read a single data value (i.e. one field). |
| * A single data value is returned, or null if no rows are returned. |
| * |
| * @author James Sutherland |
| * @since TOPLink/Java 1.2 |
| */ |
| public class ValueReadQuery extends DirectReadQuery { |
| |
| /** |
| * PUBLIC: |
| * Initialize the state of the query. |
| */ |
| public ValueReadQuery() { |
| super(); |
| this.resultType = VALUE; |
| } |
| |
| /** |
| * PUBLIC: |
| * Initialize the query to use the specified SQL string. |
| * Warning: Allowing an unverified SQL string to be passed into this |
| * method makes your application vulnerable to SQL injection attacks. |
| */ |
| public ValueReadQuery(String sqlString) { |
| super(sqlString); |
| this.resultType = VALUE; |
| } |
| |
| /** |
| * PUBLIC: |
| * Initialize the query to use the specified call. |
| */ |
| public ValueReadQuery(Call call) { |
| super(call); |
| this.resultType = VALUE; |
| } |
| |
| /** |
| * PUBLIC: |
| * Return if this is a value read query. |
| */ |
| @Override |
| public boolean isValueReadQuery() { |
| return true; |
| } |
| } |