gt:     ColumnExpr expr = (ColumnExpr) o;
context: /*
   * Copyright (c) 1998-2012 Caucho Technology -- all rights reserved
   *
   * This file is part of Resin(R) Open Source
   *
   * Each copy or derived work must preserve the copyright notice and this
   * notice unmodified.
   *
   * Resin Open Source 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.
   *
   * Resin Open Source 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, or any warranty
   * of NON-INFRINGEMENT.  See the GNU General Public License for more
   * details.
   *
   * You should have received a copy of the GNU General Public License
   * along with Resin Open Source; if not, write to the
   *   Free SoftwareFoundation, Inc.
   *   59 Temple Place, Suite 330
   *   Boston, MA 02111-1307  USA
   *
   * @author Scott Ferguson
   */
  
  package com.caucho.db.sql;
  
  import com.caucho.db.table.Column;
  import com.caucho.db.table.Table;
  import com.caucho.db.table.TableIterator;
  import com.caucho.db.table.Column.ColumnType;
  
  import java.sql.SQLException;
  import java.sql.Types;
  import java.util.logging.Logger;
  
  final class ColumnExpr extends Expr {
    private final Table _table;
  
    private final int _tableIndex;
    private final Column _column;
    private final int _columnIndex;
  
    private final String _name;
    private final Class<?> _type;
  
    ColumnExpr(String name, Table table, int tableIndex,
               int columnIndex, Class<?> type)
    {
      _name = name;
      _table = table;
      _tableIndex = tableIndex;
      _columnIndex = columnIndex;
      _column = table.getColumns()[_columnIndex];
      _type = type;
    }
  
    public Class<?> getType()
    {
      return _type;
    }
  
    @Override
    public ColumnType getTypeCode()
    {
      return getColumn().getTypeCode();
    }
  
    /**
     * Returns the column type.
     */
    public int getSQLType()
    {
      return getColumn().getSQLType();
    }
  
    /**
     * Returns any column name.
     */
    public String getName()
    {
      return _name;
    }
  
    /**
     * Returns the column.
     */
    public Column getColumn()
    {
      return _column;
    }
  
    /**
     * Returns the column's table.
     */
    public Table getTable()
    {
      return _table;
    }
  
    /**
     * Returns true if the column can contain a null value.
     */
    public boolean isNullable()
    {
      return ! _column.isNotNull();
    }
  
    /**
     * Returns true if the expression is null.
     */
    final public boolean isNull(final QueryContext context)
      throws SQLException
    {
      final TableIterator []rows = context.getTableIterators();
      final TableIterator row = rows[_tableIndex];
  
      return row.isNull(_column);
    }
  
    /**
     * Evaluates the expression as a string.
     */
    public String evalString(QueryContext context)
      throws SQLException
    {
      TableIterator []rows = context.getTableIterators();
      TableIterator row = rows[_tableIndex];
  
      return row.getString(_column);
    }
  
    public int evalInt(QueryContext context)
      throws SQLException
    {
      TableIterator []rows = context.getTableIterators();
      TableIterator row = rows[_tableIndex];
  
      return row.getInteger(_column);
    }
  
    public long evalLong(QueryContext context)
      throws SQLException
    {
      TableIterator []rows = context.getTableIterators();
      TableIterator row = rows[_tableIndex];
  
      return row.getLong(_column);
    }
  
    public final double evalDouble(final QueryContext context)
      throws SQLException
    {
      final TableIterator []rows = context.getTableIterators();
      final TableIterator row = rows[_tableIndex];
  
      return row.getDouble(_column);
    }
  
    @Override
    public int evalToBuffer(QueryContext context, byte []buffer, int offset)
      throws SQLException
    {
      TableIterator []rows = context.getTableIterators();
      TableIterator row = rows[_tableIndex];
  
      return row.getBuffer(_column, buffer, offset);
    }
  
    /**
     * Evaluates the expression, writing to the result stream.
     *
     * @param context the query context
     * @param result the output result
     */
    @Override
    public void evalToResult(QueryContext context, SelectResult result)
      throws SQLException
    {
      TableIterator []rows = context.getTableIterators();
      TableIterator row = rows[_tableIndex];
  
      row.evalToResult(_column, result);
    }
  
    public boolean evalEqual(QueryContext context, byte []matchBuffer)
      throws SQLException
    {
      TableIterator []rows = context.getTableIterators();
      TableIterator row = rows[_tableIndex];
  
      return row.isEqual(_column, matchBuffer);
    }
  
    public boolean evalEqual(QueryContext context, String string)
      throws SQLException
    {
      TableIterator []rows = context.getTableIterators();
      TableIterator row = rows[_tableIndex];
  
      return row.isEqual(_column, string);
    }
  
    public boolean equals(Object o)
    {
      if (o == null || ! ColumnExpr.class.equals(o.getClass()))
        return false;
  
  