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/*
 * Copyright (c) 1998-2018 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 java.sql.SQLException;
import java.util.ArrayList;
import java.util.logging.Logger;

class NotExpr extends Expr {
  private Expr _sub;

  NotExpr(Expr sub)
  {
    _sub = sub;
  }

  /**
   * Binds the expression to the actual tables.
   */
  public Expr bind(Query query)
    throws SQLException
  {
    _sub = _sub.bind(query);

    if (! _sub.isBoolean())
      throw new SQLException(L.l("NOT requires a boolean expression"));

    return this;
  }

  /**
   * Returns the type of the expression.
   */
  public Class getType()
  {
    return boolean.class;
  }

  /**
   * Returns the cost based on the given FromList.
   */
  public long subCost(ArrayList fromList)
  {
    return _sub.subCost(fromList);
  }

  /**
   * Evaluates the expression for nulls
   */
  public boolean isNull(QueryContext context)
    throws SQLException
  {
    return _sub.isNull(context);
  }

  /**
   * Evaluates the expression as a boolean
   *
   * @param rows the current tuple being evaluated
   *
   * @return the boolean value
   */
  public int evalBoolean(QueryContext context)
    throws SQLException
  {
    int value = _sub.evalBoolean(context);

    switch (value) {
    case TRUE:
      return FALSE;
    case FALSE:
      return TRUE;
    default:
      return UNKNOWN;
    }
  }

  /**
   * Evaluates the expression as a string.
   *
   * @param rows the current tuple being evaluated
   *
   * @return the string value
   */
  public String evalString(QueryContext context)
    throws SQLException
  {
    int value = _sub.evalBoolean(context);

    switch (value) {
    case TRUE:
      return "1";
    case FALSE:
      return "0";
    default:
      return null;
    }
  }

  /**
   * Evaluates aggregate functions during the group phase.
   *
   * @param state the current database tuple
   */
  public void evalGroup(QueryContext context)
    throws SQLException
  {
    _sub.evalGroup(context);
  }

  public String toString()
  {
    return "NOT " + _sub;
  }
}