Drizzled Public API Documentation

type_holder.h
00001 /* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
00002  *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
00003  *
00004  *  Copyright (C) 2008 Sun Microsystems, Inc.
00005  *
00006  *  This program is free software; you can redistribute it and/or modify
00007  *  it under the terms of the GNU General Public License as published by
00008  *  the Free Software Foundation; version 2 of the License.
00009  *
00010  *  This program is distributed in the hope that it will be useful,
00011  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00012  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00013  *  GNU General Public License for more details.
00014  *
00015  *  You should have received a copy of the GNU General Public License
00016  *  along with this program; if not, write to the Free Software
00017  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
00018  */
00019 
00020 #pragma once
00021 
00022 namespace drizzled {
00023 
00024 /*
00025   Item_type_holder used to store type. name, length of Item for UNIONS &
00026   derived tables.
00027 
00028   Item_type_holder do not need cleanup() because its time of live limited by
00029   single SP/PS execution.
00030 */
00031 class Item_type_holder: public Item
00032 {
00033 protected:
00034   TYPELIB *enum_set_typelib;
00035   enum_field_types fld_type;
00036 
00043   void get_full_info(Item *item);
00044 
00045   /* It is used to count decimal precision in join_types */
00046   int prev_decimal_int_part;
00047 public:
00048   Item_type_holder(Session *session, Item *item);
00049 
00056   Item_result result_type() const;
00057 
00058   enum_field_types field_type() const { return fld_type; };
00059   enum Type type() const { return TYPE_HOLDER; }
00060   double val_real();
00061   int64_t val_int();
00062   type::Decimal *val_decimal(type::Decimal *val);
00063   String *val_str(String* val);
00064 
00077   bool join_types(Session *session, Item *item);
00078 
00088   Field *make_field_by_type(Table *table);
00089 
00098   static uint32_t display_length(Item *item);
00099 
00106   static enum_field_types get_real_type(Item *item);
00107 };
00108 
00109 } /* namespace drizzled */
00110