~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_ITEM_IDENT_H

#define DRIZZLED_ITEM_IDENT_H

#include "drizzled/item.h"

namespace drizzled

{

extern uint32_t lower_case_table_names;

class Item_ident :public Item

{

protected:

  /*

    We have to store initial values of db_name, table_name and field_name

    to be able to restore them during cleanup() because they can be

    updated during fix_fields() to values from Field object and life-time

    of those is shorter than life-time of Item_field.

  */

  const char *orig_db_name;

  const char *orig_table_name;

  const char *orig_field_name;

public:

  Name_resolution_context *context;

  const char *db_name;

  const char *table_name;

  const char *field_name;

  bool alias_name_used; /* true if item was resolved against alias */

  /*

    Cached value of index for this field in table->field array, used by prep.

    stmts for speeding up their re-execution. Holds NO_CACHED_FIELD_INDEX

    if index value is not known.

  */

  uint32_t cached_field_index;

  /*

    Cached pointer to table which contains this field, used for the same reason

    by prep. stmt. too in case then we have not-fully qualified field.

    0 - means no cached value.

  */

  TableList *cached_table;

  Select_Lex *depended_from;

  Item_ident(Name_resolution_context *context_arg,

             const char *db_name_arg, const char *table_name_arg,

             const char *field_name_arg);

  Item_ident(Session *session, Item_ident *item);

  const char *full_name() const;

  void cleanup();

  bool remove_dependence_processor(unsigned char * arg);

  virtual void print(String *str, enum_query_type query_type);

  virtual bool change_context_processor(unsigned char *cntx)

    { context= (Name_resolution_context *)cntx; return false; }

  friend bool insert_fields(Session *session, Name_resolution_context *context,

                            const char *db_name,

                            const char *table_name, List_iterator<Item> *it,

                            bool any_privileges);

};

class Item_ident_for_show :public Item

{

public:

  Field *field;

  const char *db_name;

  const char *table_name;

  Item_ident_for_show(Field *par_field, const char *db_arg,

                      const char *table_name_arg)

    :field(par_field), db_name(db_arg), table_name(table_name_arg)

  {}

  enum Type type() const { return FIELD_ITEM; }

  double val_real();

  int64_t val_int();

  String *val_str(String *str);

  my_decimal *val_decimal(my_decimal *dec);

  void make_field(SendField *tmp_field);

};

} /* namespace drizzled */

#endif /* DRIZZLED_ITEM_IDENT_H */