~drizzle-trunk/drizzle/development

/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-

 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:

 *

 *  Copyright (C) 2008 Sun Microsystems, Inc.

 *

 *  This program 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; version 2 of the License.

 *

 *  This program 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 for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, write to the Free Software

 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 */

#ifndef DRIZZLED_ITEM_NULL_H

#define DRIZZLED_ITEM_NULL_H

#include "drizzled/item/basic_constant.h"

namespace drizzled

{

class Item_null :public Item_basic_constant

{

public:

  Item_null(char *name_par=0)

  {

    maybe_null= null_value= true;

    max_length= 0;

    name= name_par ? name_par : (char*) "NULL";

    fixed= 1;

    collation.set(&my_charset_bin, DERIVATION_IGNORABLE);

  }

  enum Type type() const { return NULL_ITEM; }

  bool eq(const Item *item, bool binary_cmp) const;

  double val_real();

  int64_t val_int();

  String *val_str(String *str);

  my_decimal *val_decimal(my_decimal *);

  int save_in_field(Field *field, bool no_conversions);

  int save_safe_in_field(Field *field);

  bool send(plugin::Client *client, String *str);

  enum Item_result result_type () const { return STRING_RESULT; }

  enum_field_types field_type() const   { return DRIZZLE_TYPE_NULL; }

  bool basic_const_item() const { return 1; }

  Item *clone_item() { return new Item_null(name); }

  bool is_null() { return true; }

  virtual void print(String *str, enum_query_type);

  Item *safe_charset_converter(const CHARSET_INFO * const tocs);

};

class Item_null_result :public Item_null

{

public:

  Field *result_field;

  Item_null_result() : Item_null(), result_field(0) {}

  bool is_result_field() { return result_field != 0; }

  void save_in_result_field(bool no_conversions)

  {

    save_in_field(result_field, no_conversions);

  }

};

} /* namespace drizzled */

#endif /* DRIZZLED_ITEM_NULL_H */