package org.apache.turbine.util.db;
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2001 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" and
* "Apache Turbine" must not be used to endorse or promote products
* derived from this software without prior written permission. For
* written permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* "Apache Turbine", nor may "Apache" appear in their name, without
* prior written permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
import java.math.BigDecimal;
import java.sql.Connection;
import org.apache.turbine.util.db.adapter.DB;
import com.workingdogs.village.DataSet;
import com.workingdogs.village.QueryDataSet;
import com.workingdogs.village.Record;
import com.workingdogs.village.Value;
/**
* This generator works with databases that have an sql syntax for
* getting an id prior to inserting a row into the database.
*
* @author <a href="mailto:jmcnally@collab.net">John D. McNally</a>
* @version $Id$
*/
public class SequenceIdGenerator
implements IdGenerator
{
private DB dbAdapter;
/**
* Creates an IdGenerator which will work with the specified database.
*
* @param dbAdapter, the adapter that knows the correct sql syntax.
*/
public SequenceIdGenerator(DB adapter)
{
dbAdapter = adapter;
}
/**
* Retrieves an id as an int.
*
* @param connection A Connection.
* @param keyInfo, an Object that contains additional info.
* @return An int with the value for the id.
* @exception Exception Database error.
*/
public int getIdAsInt(Connection connection, Object keyInfo)
throws Exception
{
return getIdAsVillageValue(connection, keyInfo).asInt();
}
/**
* Retrieves an id as an long.
*
* @param connection A Connection.
* @param keyInfo, an Object that contains additional info.
* @return A long with the value for the id.
* @exception Exception Database error.
*/
public long getIdAsLong(Connection connection, Object keyInfo)
throws Exception
{
return getIdAsVillageValue(connection, keyInfo).asLong();
}
/**
* Retrieves an id as a BigDecimal.
*
* @param connection A Connection.
* @param keyInfo, an Object that contains additional info.
* @return A BigDecimal id
* @exception Exception Database error.
*/
public BigDecimal getIdAsBigDecimal(Connection connection, Object keyInfo)
throws Exception
{
return getIdAsVillageValue(connection, keyInfo).asBigDecimal();
}
/**
* Retrieves an id as an String.
*
* @param connection A Connection.
* @param keyInfo, an Object that contains additional info.
* @return A String id
* @exception Exception Database error.
*/
public String getIdAsString(Connection connection, Object keyInfo)
throws Exception
{
return getIdAsVillageValue(connection, keyInfo).asString();
}
/**
* A flag to determine the timing of the id generation
*
* @return a <code>boolean</code> value
*/
public boolean isPriorToInsert()
{
return true;
}
/**
* A flag to determine the timing of the id generation
*
* @return a <code>boolean</code> value
*/
public boolean isPostInsert()
{
return false;
}
/**
* A flag to determine whether a Connection is required to
* generate an id.
*
* @return a <code>boolean</code> value
*/
public boolean isConnectionRequired()
{
return true;
}
/**
* Retrieves an id as a Village Value.
*
* @param connection A Connection.
* @param keyInfo, an Object that contains additional info.
* @return A Village Value id.
* @exception Exception Database error.
*/
private Value getIdAsVillageValue(Connection connection,
Object keyInfo)
throws Exception
{
String idSql = dbAdapter.getSequenceSql(keyInfo);
// Execute the query.
QueryDataSet qds = new QueryDataSet( connection, idSql );
Record rec;
try
{
qds.fetchRecords(1);
rec = qds.getRecord(0); // Records are 0 based.
}
finally
{
if (qds != null) qds.close();
}
return rec.getValue(1); // Values are 1 based.
}
}