001    /**
002     * =========================================
003     * LibFormula : a free Java formula library
004     * =========================================
005     *
006     * Project Info:  http://reporting.pentaho.org/libformula/
007     *
008     * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors.
009     *
010     * This library is free software; you can redistribute it and/or modify it under the terms
011     * of the GNU Lesser General Public License as published by the Free Software Foundation;
012     * either version 2.1 of the License, or (at your option) any later version.
013     *
014     * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
015     * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
016     * See the GNU Lesser General Public License for more details.
017     *
018     * You should have received a copy of the GNU Lesser General Public License along with this
019     * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
020     * Boston, MA 02111-1307, USA.
021     *
022     * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
023     * in the United States and other countries.]
024     *
025     *
026     * ------------
027     * $Id: DataTable.java 2716 2007-04-01 13:51:58Z taqua $
028     * ------------
029     * (C) Copyright 2006-2007, by Pentaho Corporation.
030     */
031    package org.jfree.formula.lvalues;
032    
033    /**
034     * A database is a two dimensional collection of data, arranged in a table.
035     * Although we do not assume that the whole database is held in memory, we
036     * allow random access of the data.
037     *
038     * Columns may have names, but there is no enforced requirement for that.
039     *
040     * As a database is not just a collection of raw data, this interface returns
041     * LValues instead of plain objects. Columns may be computed values using
042     * formulas (the exact semantics of adressing database cells in a formula is
043     * beyond the scope of this specification and is implementation specific).
044     *
045     * @author Thomas Morgner
046     */
047    public interface DataTable extends LValue
048    {
049      public int getRowCount();
050      public int getColumnCount();
051    
052      public String getColumnName (int column);
053      public LValue getValueAt (int row, int column);
054    }