Metacat

/**

 *  '$RCSfile$'

 *    Purpose: An adapter class for MS SQL Server RDBMS.

 *  Copyright: 2000 Regents of the University of California and the

 *             National Center for Ecological Analysis and Synthesis

 *    Authors: Jivka Bojilova

 *    Release: @release@

 *

 *   '$Author$'

 *     '$Date$'

 * '$Revision$'

 *

 * 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 2 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, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

package edu.ucsb.nceas.dbadapter;

import java.sql.*;

/**

 * The MS SQL Server db adapter implementation.

 */

public class SqlserverAdapter extends AbstractDatabase {

  /**

   * The SQL Server unique ID generator through use of IDENTITY key

   * The IDENTITY key is a column in the table. When record is inserted

   * in the table, SELECT @@IDENTITY can return the key generated in

   * that IDENTITY column in the same db connection.

   * This is the only way to get unique id: let the SQL Server assign

   * a value in IDENTITY column and get it afterwards for use in the

   * application.

   *

   * @param conn db connection in which to generate the unique id

   * @param tableName the name of table which unique id to generate

   * @exception SQLException <br/> any SQLException that can be thrown

   *            during the db operation

   * @return return the generated unique id as a long type

   */

  public long getUniqueID(Connection conn, String tableName)

                                         throws SQLException {

    long uniqueid = 0;

    Statement stmt = conn.createStatement();

    stmt.execute("SELECT @@IDENTITY");

    ResultSet rs = stmt.getResultSet();

    if ( rs.next() ) {

      uniqueid = rs.getLong(1);

    }

    stmt.close();

    //System.out.println("Unique ID: " + uniqueid);

    return uniqueid;

  }

  /**

   * The SQL Server's function name that gets the current date and time

   * from the database server: "getdate()"

   *

   * @return return the current date and time function name: "getdate()"

   */

  public String getDateTimeFunction() {

    //System.out.println("The date and time function: " + "getdate()");

    return "getdate()";

  }

  /**

   * The SQL Server's function name that is used to return non-NULL value

   *

   * @return return the non-NULL function name: "isnull"

   */

  public String getIsNULLFunction() {

    return "isnull";

  }

  /**

   * The SQL Server's string delimiter character: single quote (')

   *

   * @return return the string delimiter: single quote (')

   */

  public String getStringDelimiter() {

    return "'";

  }

}