Quadcap Embeddable Database

com/quadcap/sql/ViewCursor.java

Go to the documentation of this file.

package com.quadcap.sql;

/* Copyright 1999 - 2003 Quadcap Software.  All rights reserved.
 *
 * This software is distributed under the Quadcap Free Software License.
 * This software may be used or modified for any purpose, personal or
 * commercial.  Open Source redistributions are permitted.  Commercial
 * redistribution of larger works derived from, or works which bundle
 * this software requires a "Commercial Redistribution License"; see
 * http://www.quadcap.com/purchase.
 *
 * Redistributions qualify as "Open Source" under  one of the following terms:
 *   
 *    Redistributions are made at no charge beyond the reasonable cost of
 *    materials and delivery.
 *
 *    Redistributions are accompanied by a copy of the Source Code or by an
 *    irrevocable offer to provide a copy of the Source Code for up to three
 *    years at the cost of materials and delivery.  Such redistributions
 *    must allow further use, modification, and redistribution of the Source
 *    Code under substantially the same terms as this license.
 *
 * Redistributions of source code must retain the copyright notices as they
 * appear in each source code file, these license terms, and the
 * disclaimer/limitation of liability set forth as paragraph 6 below.
 *
 * Redistributions in binary form must reproduce this Copyright Notice,
 * these license terms, and the disclaimer/limitation of liability set
 * forth as paragraph 6 below, in the documentation and/or other materials
 * provided with the distribution.
 *
 * The Software is provided on an "AS IS" basis.  No warranty is
 * provided that the Software is free of defects, or fit for a
 * particular purpose.  
 *
 * Limitation of Liability. Quadcap Software shall not be liable
 * for any damages suffered by the Licensee or any third party resulting
 * from use of the Software.
 */

import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;

import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;

import java.sql.SQLException;

import com.quadcap.util.Debug;

/**
 * This cursor performs the name mapping associated with the (optional)
 * column list of the <code>CREATE VIEW</code> statement.
 *
 * @author Stan Bailes
 */
public class ViewCursor extends CursorImpl {
    Cursor                              cursor;
    View                                view;
    
    public ViewCursor(Session session, View view,
                      Cursor cursor, Vector names)
        throws SQLException
    {
        super(session, view.getName());
        this.view = view;
        this.cursor = cursor;
        if (names.size() > cursor.getColumnCount()) {
            throw new SQLException("Too many names in view column list",
                                   "42000");
        }
        if (names.size() < cursor.getColumnCount()) {
            //#ifdef TRACE
            if (Trace.bit(2)) {
                Debug.println("cursor = " + cursor);
                for (int i = 0; i < names.size(); i++) {
                    Debug.println("name[" + i + "] = " +
                                  names.elementAt(i).toString());
                }
            }
            //#endif
            throw new SQLException("Not enough names in view column list",
                                   "42000");
        }
        for (int i = 0; i < names.size(); i++) {
            String name = (String)names.elementAt(i);
            addColumn(new Column(name,
                                 cursor.getColumn(i+1).getType()));
        }
        resolveColumns();
    }

    public long size() throws SQLException { return -1; }
    
    public Row getRow() throws SQLException {
        return cursor.getRow();
    }

    public void updateRow(Row row) throws SQLException {
        view.checkRow(session, cursor, row);
        cursor.updateRow(row);
    }

    public void insertRow(Row row) throws SQLException {
        view.checkRow(session, cursor, row);
        cursor.insertRow(row);
    }

    public void deleteRow() throws SQLException {
        cursor.deleteRow();
    }

    public void beforeFirst() throws SQLException {
        cursor.beforeFirst();
    }
    
    public void afterLast() throws SQLException {
        cursor.afterLast();
    }
    
    public boolean absolute(int row) throws SQLException {
        return cursor.absolute(row);
    }
    
    public boolean next() throws SQLException {
        return cursor.next();
    }

    public boolean isWritable(int column) throws SQLException {
        return cursor.isWritable(column);
    }

    public int getColumnCount() throws SQLException {
        return cursor.getColumnCount();
    }
    public void close() throws SQLException {
        cursor.close();
    }
}