DatabaseConnection.java

/*
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program 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 General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
 *    DatabaseConnection.java
 *    Copyright (C) 2004-2012 University of Waikato, Hamilton, New Zealand
 *
 */

package weka.core.converters;

import java.io.File;
import java.sql.DatabaseMetaData;
import java.sql.SQLException;
import java.util.Properties;

import weka.core.RevisionUtils;
import weka.experiment.DatabaseUtils;

/**
 * Connects to a database.
 *
 * @author Len Trigg (trigg@cs.waikato.ac.nz)
 * @author Stefan Mutter (mutter@cs.waikato.ac.nz)
 * @version $Revision: 8034 $
 */
public class DatabaseConnection 
  extends DatabaseUtils {

  /** for serialization */
  static final long serialVersionUID = 1673169848863178695L;
  
  /**
   * Sets up the database drivers.
   *
   * @throws Exception if an error occurs
   */
  public DatabaseConnection() throws Exception {
    super();
  }
  
  /**
   * Reads the properties from the specified file and sets up the database drivers.
   *
   * @param propsFile	the props file to load, ignored if null or pointing 
   * 			to a directory
   * @throws Exception 	if an error occurs
   */
  public DatabaseConnection(File propsFile) throws Exception {
    super(propsFile);
  }
  
  /**
   * Uses the specified properties to set up the database drivers.
   *
   * @param props	the properties to use, ignored if null
   * @throws Exception 	if an error occurs
   */
  public DatabaseConnection(Properties props) throws Exception {
    super(props);
  }

  /**
   * Returns the underlying properties object.
   * 
   * @return		the properties object
   */
  public Properties getProperties() {
    return PROPERTIES;
  }
  
  /** 
   * Check if the property checkUpperCaseNames in the DatabaseUtils file is 
   * set to true or false.
   *
   * @return  	true if the property checkUpperCaseNames in the DatabaseUtils 
   * 		file is set to true, false otherwise.
   */
  public boolean getUpperCase(){
    return m_checkForUpperCaseNames;
  }
  
  /**
   * Gets meta data for the database connection object.
   *
   * @return the meta data.
   * @throws Exception if an error occurs
   */
  public DatabaseMetaData getMetaData() throws Exception{
    if (!isConnected())
      throw new IllegalStateException("Not connected, please connect first!");
    
    return m_Connection.getMetaData();
  }
  
  /**
   * Dewtermines if the current query retrieves a result set or updates a table
   *
   * @return the update count (-1 if the query retrieves a result set).
   * @throws SQLException if an error occurs
   */
  public int getUpdateCount() throws SQLException {
    if (!isConnected())
      throw new IllegalStateException("Not connected, please connect first!");
    
    return m_PreparedStatement.getUpdateCount();
  }
  
  /**
   * Returns the revision string.
   * 
   * @return		the revision
   */
  public String getRevision() {
    return RevisionUtils.extract("$Revision: 8034 $");
  }
}