~drizzle-trunk/drizzle/development

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

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

 *

 *  Copyright (C) 2008 MySQL

 *

 *  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; either version 2 of the License, or

 *  (at your option) any later version.

 *

 *  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_FIELD_NULL_H

#define DRIZZLED_FIELD_NULL_H

#include <drizzled/field/str.h>

namespace drizzled

{

/*

 * Everything saved in this will disappear. It will always return NULL

 */

class Field_null :public Field_str

{

  static unsigned char null[1];

public:

  using Field::store;

  using Field::val_str;

  using Field::cmp;

  using Field::val_int;

  Field_null(unsigned char *ptr_arg,

             uint32_t len_arg,

             const char *field_name_arg,

             const CHARSET_INFO * const cs)

    :Field_str(ptr_arg,

               len_arg,

               null,

               1,

	             field_name_arg,

               cs)

  {}

  enum_field_types type() const

  {

    return DRIZZLE_TYPE_NULL;

  }

  int  store(const char *, uint32_t, const CHARSET_INFO * const)

  {

    null[0]= 1;

    return 0;

  }

  int store(double)

  {

    null[0]= 1;

    return 0;

  }

  int store(int64_t, bool)

  {

    null[0]= 1;

    return 0;

  }

  int store_decimal(const my_decimal *)

  {

    null[0]= 1;

    return 0;

  }

  int reset(void)

  {

    return 0;

  }

  double val_real(void)

  {

    return 0.0;

  }

  int64_t val_int(void)

  {

    return 0;

  }

  my_decimal *val_decimal(my_decimal *)

  {

    return 0;

  }

  String *val_str(String *, String *value2)

  {

    value2->length(0);

    return value2;

  }

  int cmp(const unsigned char *, const unsigned char *)

  {

    return 0;

  }

  void sort_string(unsigned char *, uint32_t)

  {}

  uint32_t pack_length() const

  {

    return 0;

  }

  void sql_type(String &str) const;

  uint32_t size_of() const

  {

    return sizeof(*this);

  }

  uint32_t max_display_length()

  {

    return 4;

  }

};

} /* namespace drizzled */

#endif /* DRIZZLED_FIELD_NULL_H */