~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

 *

 *  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_FOREIGN_KEY_H

#define DRIZZLED_FOREIGN_KEY_H

#include "drizzled/sql_alloc.h"

#include "drizzled/key.h"

#include "drizzled/key_part_spec.h"

#include "drizzled/sql_list.h"

#include "drizzled/cursor.h" /* for default_key_create_info */

class Item;

class Table_ident;

typedef struct st_mem_root MEM_ROOT;

class Foreign_key: public Key 

{

public:

  enum fk_match_opt 

  {

    FK_MATCH_UNDEF, 

    FK_MATCH_FULL, 

    FK_MATCH_PARTIAL, 

    FK_MATCH_SIMPLE

  };

  enum fk_option 

  {

    FK_OPTION_UNDEF, 

    FK_OPTION_RESTRICT, 

    FK_OPTION_CASCADE, 

    FK_OPTION_SET_NULL, 

    FK_OPTION_NO_ACTION, 

    FK_OPTION_DEFAULT

  };

  Table_ident *ref_table;

  List<Key_part_spec> ref_columns;

  uint32_t delete_opt, update_opt, match_opt;

  Foreign_key(const LEX_STRING &name_arg,

              List<Key_part_spec> &cols,

              Table_ident *table,

              List<Key_part_spec> &ref_cols,

              uint32_t delete_opt_arg,

              uint32_t update_opt_arg,

              uint32_t match_opt_arg) :

    Key(FOREIGN_KEY, name_arg, &default_key_create_info, 0, cols), ref_table(table),

    ref_columns(ref_cols),

    delete_opt(delete_opt_arg),

    update_opt(update_opt_arg),

    match_opt(match_opt_arg)

  { }

  /**

   * Constructs an (almost) deep copy of this foreign key. Only those

   * elements that are known to never change are not copied.

   * If out of memory, a partial copy is returned and an error is set

   * in Session.

   */

  Foreign_key(const Foreign_key &rhs, MEM_ROOT *mem_root);

  /**

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

   * 

   * @see comment for Key_part_spec::clone

   */

  virtual Key *clone(MEM_ROOT *mem_root) const

  {

    return new (mem_root) Foreign_key(*this, mem_root);

  }

  /* Used to validate foreign key options */

  bool validate(List<CreateField> &table_fields);

};

#endif /* DRIZZLED_FOREIGN_KEY_H */