mysql.java

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/*  Sesame - Storage and Querying architecture for RDF and RDF Schema
 *  Copyright (C) 2001-2005 Aduna
 *
 *  Contact: 
 *  	Aduna
 *  	Prinses Julianaplein 14 b
 *  	3817 CS Amersfoort
 *  	The Netherlands
 *  	tel. [phone]
 *  	fax. [phone]
 *
 *  	http://aduna.biz/
 *  	http://www.openrdf.org/
 *  
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package org.openrdf.sesame.sailimpl.rdbms;

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Types;

import org.openrdf.util.log.ThreadLog;

/**
 * Defines MySQL specific SQL syntax. 
 *
 * @author Arjohn Kampman
 */
public class MySQL extends RDBMS {

	/**
	 * Initializes MySQL specific SQL syntax.
	 */
	public MySQL() {
		super();

		// the default character types are case-insensitive in
		// MySQL, define case-sensitive alternatives:
		LOCALNAME = "VARCHAR(255) BINARY";
		LANGUAGE = "VARCHAR(16) BINARY";
		LABEL = "BLOB";
		LABEL_TYPE = Types.BLOB;
		PREFIX = "VARCHAR(16) BINARY";
		NAME = "BLOB";
		NAME_TYPE = Types.BLOB;
		BOOLEAN = "BOOL";
		TRUE = "1";
		FALSE = "0";
		INFOFIELD = "VARCHAR(255) BINARY";
	}

	protected void _initConstants(DatabaseMetaData metaData)
		throws SQLException
	{
		super._initConstants(metaData);

		int majorVersion = metaData.getDatabaseMajorVersion();
		int minorVersion = metaData.getDatabaseMinorVersion();

		if (majorVersion == 4 && minorVersion >= 1 || majorVersion >= 5) {
			// MySQL 4.1 and higher support character set and -collation specifications
			ThreadLog.trace("Detected MySQL 4.1 or newer, using case-sensitive utf-8 character columns");

			LOCALNAME = "VARCHAR(255) CHARACTER SET utf8 COLLATE utf8_bin";
			LANGUAGE = "VARCHAR(16) CHARACTER SET utf8 COLLATE utf8_bin";
			LABEL = "TEXT CHARACTER SET utf8 COLLATE utf8_bin";
			LABEL_TYPE = Types.LONGVARCHAR;
			PREFIX = "VARCHAR(16) CHARACTER SET utf8 COLLATE utf8_bin";
			NAME = "TEXT CHARACTER SET utf8 COLLATE utf8_bin";
			NAME_TYPE = Types.LONGVARCHAR;
			INFOFIELD = "VARCHAR(255) CHARACTER SET utf8 COLLATE utf8_bin";
		}
	}

	/**
	 * Overrides dropIndex in RDBMS. In MySQL, an index is identified by
	 * both its index and table name.
	 **/
	public void dropIndex(String table, String column)
		throws SQLException
	{
		executeUpdate("DROP INDEX " + getIndexName(table, column) + " ON " + table);
	}

	// Overrides RDBMS.optimizeTable()
	public void optimizeTable(String tableName)
		throws SQLException
	{
		//ThreadLog.trace("optimizing table " + tableName);
		Connection con = getConnection();
		Statement st = con.createStatement();

		ResultSet rs = st.executeQuery("OPTIMIZE TABLE " + tableName);

		rs.close();
		st.close();
		con.close();
		//ThreadLog.trace("done optimizing table");
	}

	// Overrides RDBMS._clearTable()
	protected void _clearTable(String tableName)
		throws SQLException
	{
		executeUpdate("TRUNCATE TABLE " + tableName);
	}

	public void renameTableColumn(String tableName, String currentColumnName, String newColumnName, String columnSignature)
		throws SQLException
	{
		executeUpdate("ALTER TABLE " + tableName + " CHANGE " + currentColumnName + " " + newColumnName + " " + columnSignature);
	}
}