Drizzled Public API Documentation

rollup_const.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 #include <drizzled/function/func.h>
00023 
00024 
00025 namespace drizzled
00026 {
00027 
00028 /*
00029   Objects of this class are used for ROLLUP queries to wrap up
00030   each constant item referred to in GROUP BY list.
00031 */
00032 
00033 class Item_func_rollup_const :public Item_func
00034 {
00035 public:
00036   Item_func_rollup_const(Item *a) :Item_func(a)
00037   {
00038     name= a->name;
00039     name_length= a->name_length;
00040   }
00041   double val_real() { return args[0]->val_real(); }
00042   int64_t val_int() { return args[0]->val_int(); }
00043   String *val_str(String *str) { return args[0]->val_str(str); }
00044   type::Decimal *val_decimal(type::Decimal *dec) { return args[0]->val_decimal(dec); }
00045   const char *func_name() const { return "rollup_const"; }
00046   bool const_item() const { return 0; }
00047   Item_result result_type() const { return args[0]->result_type(); }
00048   void fix_length_and_dec()
00049   {
00050     collation= args[0]->collation;
00051     max_length= args[0]->max_length;
00052     decimals=args[0]->decimals;
00053     /* The item could be a NULL constant. */
00054     null_value= args[0]->is_null();
00055   }
00056 };
00057 
00058 } /* namespace drizzled */
00059