/*
 * Copyright (c) 2013, OpenCloudDB/MyCAT and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software;Designed and Developed mainly by many Chinese 
 * opensource volunteers. you can redistribute it and/or modify it under the 
 * terms of the GNU General Public License version 2 only, as published by the
 * Free Software Foundation.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 * 
 * Any questions about this component can be directed to it's project Web address 
 * https://code.google.com/p/opencloudb/.
 *
 */
package com.akiban.sql.parser;

import com.akiban.sql.StandardException;

/**
 * A DistinctNode represents a result set for a disinct operation
 * on a select.  It has the same description as its input result set.
 *
 * For the most part, it simply delegates operations to its childResultSet,
 * which is currently expected to be a ProjectRestrictResultSet generated
 * for a SelectNode.
 *
 * NOTE: A DistinctNode extends FromTable since it can exist in a FromList.
 *
 */
public class DistinctNode extends SingleChildResultSetNode
{
    boolean inSortedOrder;

    /**
     * Initializer for a DistinctNode.
     *
     * @param childResult The child ResultSetNode
     * @param inSortedOrder Whether or not the child ResultSetNode returns its
     *                                          output in sorted order.
     * @param tableProperties Properties list associated with the table
     *
     * @exception StandardException Thrown on error
     */
    public void init(Object childResult,
                     Object inSortedOrder,
                     Object tableProperties) 
            throws StandardException {
        super.init(childResult, tableProperties);
        this.inSortedOrder = ((Boolean)inSortedOrder).booleanValue();
    }

    /**
     * Fill this node with a deep copy of the given node.
     */
    public void copyFrom(QueryTreeNode node) throws StandardException {
        super.copyFrom(node);

        DistinctNode other = (DistinctNode)node;
        this.inSortedOrder = other.inSortedOrder;
    }

}