~drizzle-trunk/drizzle/development

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/* - 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>

/*
 * 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;
  }
};

#endif /* DRIZZLED_FIELD_NULL_H */