package org.apache.ddlutils.platform.hsqldb;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
import org.apache.ddlutils.Platform;
import org.apache.ddlutils.alteration.AddColumnChange;
import org.apache.ddlutils.alteration.RemoveColumnChange;
import org.apache.ddlutils.alteration.TableChange;
import org.apache.ddlutils.model.Database;
import org.apache.ddlutils.model.Table;
import org.apache.ddlutils.platform.SqlBuilder;
/**
* The SQL Builder for the HsqlDb database.
*
* @version $Revision: 518485 $
*/
public class HsqlDbBuilder extends SqlBuilder
{
/**
* Creates a new builder instance.
*
* @param platform The plaftform this builder belongs to
*/
public HsqlDbBuilder(Platform platform)
{
super(platform);
addEscapedCharSequence("'", "''");
}
/**
* {@inheritDoc}
*/
public void dropTable(Table table) throws IOException
{
print("DROP TABLE ");
printIdentifier(getTableName(table));
print(" IF EXISTS");
printEndOfStatement();
}
/**
* {@inheritDoc}
*/
public String getSelectLastIdentityValues(Table table)
{
return "CALL IDENTITY()";
}
/**
* {@inheritDoc}
*/
protected void processTableStructureChanges(Database currentModel,
Database desiredModel,
Table sourceTable,
Table targetTable,
Map parameters,
List changes) throws IOException
{
// HsqlDb can only drop columns that are not part of a primary key
for (Iterator changeIt = changes.iterator(); changeIt.hasNext();)
{
TableChange change = (TableChange)changeIt.next();
if ((change instanceof RemoveColumnChange) &&
((RemoveColumnChange)change).getColumn().isPrimaryKey())
{
return;
}
}
// in order to utilize the ALTER TABLE ADD COLUMN BEFORE statement
// we have to apply the add column changes in the correct order
// thus we first gather all add column changes and then execute them
// Since we get them in target table column order, we can simply
// iterate backwards
ArrayList addColumnChanges = new ArrayList();
for (Iterator changeIt = changes.iterator(); changeIt.hasNext();)
{
TableChange change = (TableChange)changeIt.next();
if (change instanceof AddColumnChange)
{
addColumnChanges.add(change);
changeIt.remove();
}
}
for (ListIterator changeIt = addColumnChanges.listIterator(addColumnChanges.size()); changeIt.hasPrevious();)
{
AddColumnChange addColumnChange = (AddColumnChange)changeIt.previous();
processChange(currentModel, desiredModel, addColumnChange);
changeIt.remove();
}
for (Iterator changeIt = changes.iterator(); changeIt.hasNext();)
{
TableChange change = (TableChange)changeIt.next();
if (change instanceof RemoveColumnChange)
{
RemoveColumnChange removeColumnChange = (RemoveColumnChange)change;
processChange(currentModel, desiredModel, removeColumnChange);
changeIt.remove();
}
}
}
/**
* Processes the addition of a column to a table.
*
* @param currentModel The current database schema
* @param desiredModel The desired database schema
* @param change The change object
*/
protected void processChange(Database currentModel,
Database desiredModel,
AddColumnChange change) throws IOException
{
print("ALTER TABLE ");
printlnIdentifier(getTableName(change.getChangedTable()));
printIndent();
print("ADD COLUMN ");
writeColumn(change.getChangedTable(), change.getNewColumn());
if (change.getNextColumn() != null)
{
print(" BEFORE ");
printIdentifier(getColumnName(change.getNextColumn()));
}
printEndOfStatement();
change.apply(currentModel, getPlatform().isDelimitedIdentifierModeOn());
}
/**
* Processes the removal of a column from a table.
*
* @param currentModel The current database schema
* @param desiredModel The desired database schema
* @param change The change object
*/
protected void processChange(Database currentModel,
Database desiredModel,
RemoveColumnChange change) throws IOException
{
print("ALTER TABLE ");
printlnIdentifier(getTableName(change.getChangedTable()));
printIndent();
print("DROP COLUMN ");
printIdentifier(getColumnName(change.getColumn()));
printEndOfStatement();
change.apply(currentModel, getPlatform().isDelimitedIdentifierModeOn());
}
}