~drizzle-trunk/drizzle/development

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

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

 *

 *  Copyright (C) 2008-2009 Sun Microsystems

 *

 *  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_CREATE_FIELD_H

#define DRIZZLED_CREATE_FIELD_H

#include "drizzled/field.h"

namespace drizzled

{

class Item;

typedef struct st_typelib TYPELIB;

/**

 * Class representing a field in a CREATE TABLE statement.

 *

 * Basically, all information for a new or altered field

 * definition is contained in the Create_field class.

 */

class CreateField :public memory::SqlAlloc

{

public:

  const char *field_name; /**< Name of the field to be created */

  const char *change; /**< If done with alter table */

  const char *after; /**< Put this new Field after this Field */

  LEX_STRING comment; /**< A comment for this field */

  Item *def; /**< Default value for the new field */

  enum enum_field_types sql_type; /**< The data type of the new field */

  /**

   * At various stages in execution this can be length of field in bytes or

   * max number of characters.

   */

  uint32_t length;

  /**

   * The value of `length' as set by parser: is the number of characters

   * for most of the types, or of bytes for BLOBs or numeric types.

   */

  uint32_t char_length;

  uint32_t decimals;

  uint32_t flags;

  uint32_t pack_length;

  uint32_t key_length;

  Field::utype unireg_check; /**< See Field::unireg_check */

  TYPELIB *interval; /**< Which interval to use (ENUM types..) */

  List<String> interval_list;

  const CHARSET_INFO *charset; /**< Character set for the column -- @TODO should be deleted */

  Field *field; // For alter table

  uint8_t interval_id;	// For rea_create_table

  uint32_t offset;

  CreateField() :after(0) {}

  CreateField(Field *field, Field *orig_field);

  /* Used to make a clone of this object for ALTER/CREATE TABLE */

  CreateField *clone(memory::Root *mem_root) const

    { return new (mem_root) CreateField(*this); }

  void create_length_to_internal_length(void);

  inline enum column_format_type column_format() const

  {

    return (enum column_format_type)

      ((flags >> COLUMN_FORMAT_FLAGS) & COLUMN_FORMAT_MASK);

  }

  /**

   * Init for a tmp table field. To be extended if need be. 

   *

   * @note This is currently ONLY used in Item_sum_distinct::setup()

   */

  void init_for_tmp_table(enum_field_types sql_type_arg,

                          uint32_t max_length,

                          uint32_t decimals,

                          bool maybe_null);

  /**

    Initialize field definition for create.

    @param session                   Thread handle

    @param fld_name              Field name

    @param fld_type              Field type

    @param fld_length            Field length

    @param fld_decimals          Decimal (if any)

    @param fld_type_modifier     Additional type information

    @param fld_default_value     Field default value (if any)

    @param fld_on_update_value   The value of ON UPDATE clause

    @param fld_comment           Field comment

    @param fld_change            Field change

    @param fld_interval_list     Interval list (if any)

    @param fld_charset           Field charset

    @retval

      false on success

    @retval

      true  on error

  */

  bool init(Session *session,

            char *field_name,

            enum_field_types type,

            char *length,

            char *decimals,

            uint32_t type_modifier,

            Item *default_value,

            Item *on_update_value,

            LEX_STRING *comment,

            char *change,

            List<String> *interval_list,

            const CHARSET_INFO * const cs,

            uint32_t uint_geom_type,

            enum column_format_type column_format);

};

} /* namespace drizzled */

#endif /* DRIZZLED_CREATE_FIELD_H */