Quadcap Embeddable Database

com/quadcap/sql/SelectStmt.java

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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:
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 *    Redistributions are made at no charge beyond the reasonable cost of
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 *
 *    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
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 * provided that the Software is free of defects, or fit for a
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 */

import java.util.Vector;

import java.io.IOException;

import java.sql.ResultSet;
import java.sql.SQLException;

import com.quadcap.sql.index.Btree;

import com.quadcap.util.Debug;

/**
 * Implementation of SQL <b>SELECT</b> statement.
 *
 * @author Stan Bailes
 */




public class SelectStmt implements Stmt {
    TableExpression                     expression;
    Vector                              order;

    public SelectStmt() {}
    
    public SelectStmt(TableExpression expression) {
        this.expression = expression;
    }

    public void setOrder(Vector order) {
        this.order = order;
    }

    public void execute(Session session) throws IOException, SQLException {
        Cursor c = expression.getCursor(session, null);
        if (order != null) {
            if (c instanceof DistinctCursor) {
                ((DistinctCursor)c).setOrder(order);
            } else {
                c = new OrderByCursor(session, c, order);
            }
        }
        session.addCursor(c);
        Database db = session.getDatabase();
        QedResultSet rs = db.getDriver().makeResultSet(c);
        session.setResultSet(rs);
    }
}