/******************************************************************************* | |
* Copyright (c) 1998, 2013 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 v1.0 and Eclipse Distribution License v. 1.0 | |
* which accompanies this distribution. | |
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html | |
* and the Eclipse Distribution License is available at | |
* http://www.eclipse.org/org/documents/edl-v10.php. | |
* | |
* Contributors: | |
* Oracle - initial API and implementation from Oracle TopLink | |
* Nov 5, 2013-2.5 Chris Delahunt | |
* - 421109: DB2 AS400 doesn't support "USE AND KEEP UPDATE LOCKS" used for pessimistic locking | |
******************************************************************************/ | |
package org.eclipse.persistence.platform.database; | |
import org.eclipse.persistence.expressions.ExpressionOperator; | |
/** | |
* <b>Purpose</b>: Provides DB2 Mainframe specific behavior.<p> | |
* This provides for some additional compatibility in certain DB2 versions on OS390. | |
* <b>Responsibilities</b>: | |
* <ul> | |
* <li>Specialized CONCAT syntax | |
* </ul> | |
* | |
* @since TopLink 3.0.3 | |
*/ | |
public class DB2MainframePlatform extends DB2Platform { | |
public DB2MainframePlatform() { | |
super(); | |
this.pingSQL = "SELECT COUNT(*) from SYSIBM.SYSDUMMY1 WHERE 1 = 0"; | |
} | |
/** | |
* Initialize any platform-specific operators | |
*/ | |
@Override | |
protected void initializePlatformOperators() { | |
super.initializePlatformOperators(); | |
addOperator(ExpressionOperator.simpleLogicalNoParens(ExpressionOperator.Concat, "CONCAT")); | |
} | |
/** | |
* INTERNAL: | |
* Used for pessimistic locking in DB2. | |
* Without the "WITH RS" the lock is not held. | |
* AS/400 does not support UPDATE type lock, so EXCLUSIVE is used instead. | |
*/ | |
@Override | |
public String getSelectForUpdateString() { | |
return " FOR READ ONLY WITH RS USE AND KEEP EXCLUSIVE LOCKS"; | |
} | |
/** | |
* INTERNAL: | |
* Return if brackets can be used in the ON clause for outer joins. | |
* Some DB2 versions on OS390 do not allow this. | |
*/ | |
@Override | |
public boolean supportsOuterJoinsWithBrackets() { | |
return false; | |
} | |
} |