org.eclipse.persistence.tools.schemaframework.SequenceDefinition Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of eclipselink Show documentation
EclipseLink build based upon Git transaction f2b9fc5
The newest version!
/*
 * Copyright (c) 1998, 2024 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
//     02/04/2013-2.5 Guy Pelletier
//       - 389090: JPA 2.1 DDL Generation Support
package org.eclipse.persistence.tools.schemaframework;

import org.eclipse.persistence.exceptions.DatabaseException;
import org.eclipse.persistence.exceptions.EclipseLinkException;
import org.eclipse.persistence.exceptions.ValidationException;
import org.eclipse.persistence.internal.sessions.AbstractSession;
import org.eclipse.persistence.sequencing.Sequence;

import java.io.Writer;

/**
 * 
 * Purpose: Allow a generic way of creating sequences on the different platforms,
 * and allow optional parameters to be specified.
 * 
 */
public abstract class SequenceDefinition extends DatabaseObjectDefinition {
    protected Sequence sequence;

    protected SequenceDefinition(String name) {
        super();
        this.name = name;
    }

    protected SequenceDefinition(Sequence sequence) {
        super();
        this.sequence = sequence;
        this.name = sequence.getName();
    }

    /**
     * INTERNAL:
     * Verify whether the sequence exists.
     */
    public abstract boolean checkIfExist(AbstractSession session) throws DatabaseException;

    /**
     * INTERNAL:
     * Indicates whether alter is supported
     */
    public boolean isAlterSupported(AbstractSession session) {
        return false;
    }

    /**
     * INTERNAL:
     */
    public boolean isTableSequenceDefinition() {
        return false;
    }

    /**
     * INTERNAL:
     * By default, does nothing.
     */
    public void alterOnDatabase(AbstractSession session) throws EclipseLinkException {
    }

    /**
     * INTERNAL:
     * Execute the SQL required to alter sequence.
     * By default, does nothing.
     */
    public void alter(AbstractSession session, Writer writer) throws ValidationException {
    }

    /**
     * INTERNAL:
     * Creates this sequence definition on the database.  If it already exists, the method will attempt
     * to alter it based on what the platform supports.
     */
    @Override
    public void createOnDatabase(AbstractSession session) throws EclipseLinkException {
        boolean exists = false;
        final boolean loggingOff = session.isLoggingOff();
        try {
            session.setLoggingOff(true);
            exists = checkIfExist(session);
        } finally {
            session.setLoggingOff(loggingOff);
        }
        if (exists) {
            if (this.isAlterSupported(session)) {
                alterOnDatabase(session);
            }
        } else {
            super.createOnDatabase(session);
        }
    }

    /**
     * INTERNAL:
     * Return a TableDefinition
     */
    public TableDefinition buildTableDefinition() {
        return null;
    }
}