/*
 *   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/>.
 */

/*
 *    InstanceQueryAdapter.java
 *    Copyright (C) 2011-2012 University of Waikato, Hamilton, New Zealand
 *
 */

package weka.experiment;

/**
 * An interface implemented by InstanceQuery and any user class that is
 * to be passed as the first argument to
 * InstanceQuery.retrieveInstances(InstanceQueryAdapter, ResultSet).
 *
 * @author Wes Munsil (wes_munsil@cytoanalytics.com)
 * @version $Revision: 8034 $
 */
public interface InstanceQueryAdapter
{
  /**
   * returns key column headings in their original case. Used for
   * those databases that create uppercase column names.
   *
   * @param columnName    the column to retrieve the original case for
   * @return        the original case
   */
  public String attributeCaseFix(String columnName);

  /**
   * Gets whether there should be printed some debugging output to stderr or not.
   *
   * @return         true if output should be printed
   */
  public boolean getDebug();

  /**
   * Gets whether data is to be returned as a set of sparse instances
   * @return true if data is to be encoded as sparse instances
   */
  public boolean getSparseData();

  /**
   * translates the column data type string to an integer value that indicates
   * which data type / get()-Method to use in order to retrieve values from the
   * database (see DatabaseUtils.Properties, InstanceQuery()). Blanks in the type
   * are replaced with underscores "_", since Java property names can't contain blanks.
   *
   * @param type     the column type as retrieved with
   *             java.sql.MetaData.getColumnTypeName(int)
   * @return         an integer value that indicates
   *             which data type / get()-Method to use in order to
   *             retrieve values from the
   */
  public int translateDBColumnType(String type);
}