package org.apache.ddlutils.task;
/*
* 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.File;
import java.io.FileWriter;
import java.sql.Connection;
import java.sql.SQLException;
import org.apache.ddlutils.Platform;
import org.apache.ddlutils.model.Database;
import org.apache.ddlutils.platform.CreationParameters;
import org.apache.tools.ant.BuildException;
/**
* Parses the schema XML files specified in the enclosing task, and writes the SQL statements
* necessary to create this schema in the database, to a file. Note that this SQL is
* database specific and hence this subtask requires that for the enclosing task, either a
* data source is specified (via the <code>database</code> sub element) or the
* <code>databaseType</code> attribute is used to specify the database type.
*
* @version $Revision: 289996 $
* @ant.task name="writeSchemaSqlToFile"
*/
public class WriteSchemaSqlToFileCommand extends DatabaseCommandWithCreationParameters
{
/** The file to output the DTD to. */
private File _outputFile;
/** Whether to alter or re-set the database if it already exists. */
private boolean _alterDb = true;
/** Whether to drop tables and the associated constraints if necessary. */
private boolean _doDrops = true;
/**
* Specifies the name of the file to write the SQL commands to.
*
* @param outputFile The output file
* @ant.required
*/
public void setOutputFile(File outputFile)
{
_outputFile = outputFile;
}
/**
* Determines whether to alter the database if it already exists, or re-set it.
*
* @return <code>true</code> if to alter the database
*/
protected boolean isAlterDatabase()
{
return _alterDb;
}
/**
* Specifies whether DdlUtils shall generate SQL to alter an existing database rather
* than SQL for clearing it and creating it new.
*
* @param alterTheDb <code>true</code> if SQL to alter the database shall be created
* @ant.not-required Per default SQL for altering the database is created
*/
public void setAlterDatabase(boolean alterTheDb)
{
_alterDb = alterTheDb;
}
/**
* Determines whether SQL is generated to drop tables and the associated constraints
* if necessary.
*
* @return <code>true</code> if drops SQL shall be generated if necessary
*/
protected boolean isDoDrops()
{
return _doDrops;
}
/**
* Specifies whether SQL for dropping tables, external constraints, etc. is created if necessary.
* Note that this is only relevant when <code>alterDatabase</code> is <code>false</code>.
*
* @param doDrops <code>true</code> if drops shall be performed if necessary
* @ant.not-required Per default, drop SQL statements are created
*/
public void setDoDrops(boolean doDrops)
{
_doDrops = doDrops;
}
/**
* {@inheritDoc}
*/
public void execute(DatabaseTaskBase task, Database model) throws BuildException
{
if (_outputFile == null)
{
throw new BuildException("No output file specified");
}
if (_outputFile.exists() && !_outputFile.canWrite())
{
throw new BuildException("Cannot overwrite output file "+_outputFile.getAbsolutePath());
}
Platform platform = getPlatform();
boolean isCaseSensitive = platform.isDelimitedIdentifierModeOn();
CreationParameters params = getFilteredParameters(model, platform.getName(), isCaseSensitive);
try
{
FileWriter writer = new FileWriter(_outputFile);
platform.setScriptModeOn(true);
if (platform.getPlatformInfo().isSqlCommentsSupported())
{
// we're generating SQL comments if possible
platform.setSqlCommentsOn(true);
}
platform.getSqlBuilder().setWriter(writer);
boolean shouldAlter = isAlterDatabase();
if (shouldAlter)
{
if (getDataSource() == null)
{
shouldAlter = false;
_log.warn("Cannot alter the database because no database connection was specified." +
" SQL for database creation will be generated instead.");
}
else
{
try
{
Connection connection = getDataSource().getConnection();
connection.close();
}
catch (SQLException ex)
{
shouldAlter = false;
_log.warn("Could not establish a connection to the specified database, " +
"so SQL for database creation will be generated instead.",
ex);
}
}
}
if (shouldAlter)
{
Database currentModel = (getCatalogPattern() != null) || (getSchemaPattern() != null) ?
platform.readModelFromDatabase("unnamed", getCatalogPattern(), getSchemaPattern(), null) :
platform.readModelFromDatabase("unnamed");
platform.getSqlBuilder().alterDatabase(currentModel, model, params);
}
else
{
platform.getSqlBuilder().createTables(model, params, _doDrops);
}
writer.close();
_log.info("Written schema SQL to " + _outputFile.getAbsolutePath());
}
catch (Exception ex)
{
handleException(ex, ex.getMessage());
}
}
}