/*
 * 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;

import java.util.Properties;

/**
 * The CurrentOf operator is used by positioned DELETE 
 * and UPDATE to get the current row and location
 * for the target cursor.    The bind() operations for 
 * positioned DELETE and UPDATE add a column to 
 * the select list under the statement for the row location 
 * accessible from this node.
 *
 * This node is placed in the from clause of the select
 * generated for the delete or update operation. It acts
 * much like a FromBaseTable, using the information about
 * the target table of the cursor to provide information.
 *
 */
public class CurrentOfNode extends FromTable 
{
    private String cursorName;

    //
    // initializer
    //
    public void init(Object correlationName, Object cursor, Object tableProperties) {
        super.init(correlationName, tableProperties);
        cursorName = (String)cursor;
    }

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

        CurrentOfNode other = (CurrentOfNode)node;
        this.cursorName = other.cursorName;
    }

    /**
     * Prints the sub-nodes of this object.  See QueryTreeNode.java for
     * how tree printing is supposed to work.
     *
     * @param depth The depth of this node in the tree
     */
    public void printSubNodes(int depth) {
        super.printSubNodes(depth);

        printLabel(depth, "cursor: ");
    }

    /**
     * Convert this object to a String.  See comments in QueryTreeNode.java
     * for how this should be done for tree printing.
     *
     * @return This object as a String
     */
    public String toString() {
        return "preparedStatement: " +
            cursorName + "\n" +
            super.toString();
    }

    public String getCursorName() {
        return cursorName;
    }

}