Drizzled Public API Documentation

random_number.cc

00001 /* - mode: c; c-basic-offset: 2; indent-tabs-mode: nil; -*-
00002  *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
00003  *
00004  *  Copyright (C) 2010 Brian Aker
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; either version 2 of the License, or
00009  *  (at your option) any later version.
00010  *
00011  *  This program is distributed in the hope that it will be useful,
00012  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014  *  GNU General Public License for more details.
00015  *
00016  *  You should have received a copy of the GNU General Public License
00017  *  along with this program; if not, write to the Free Software
00018  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
00019  */
00020 
00021 #include <config.h>
00022 
00023 #include <plugin/utility_dictionary/dictionary.h>
00024 
00025 #include <drizzled/atomics.h>
00026 #include <drizzled/session.h>
00027 #include <drizzled/sql_lex.h>
00028 
00029 using namespace drizzled;
00030 using namespace std;
00031 
00032 utility_dictionary::RandomNumber::RandomNumber() :
00033   plugin::TableFunction("DATA_DICTIONARY", "RANDOM_NUMBER")
00034 {
00035   add_field("VALUE", plugin::TableFunction::NUMBER, 0, false);
00036 }
00037 
00038 bool utility_dictionary::RandomNumber::Generator::populate()
00039 {
00040   if (lex().isSumExprUsed() && count > 0)
00041     return false;
00042 
00043   if (lex().current_select->group_list.elements && count > 0)
00044     return false;
00045 
00046   if (lex().current_select->explicit_limit or count == 0)
00047   {
00048     push(static_cast<int64_t>(random()));
00049   }
00050   else
00051   {
00052     return false;
00053   }
00054 
00055   count++;
00056 
00057   return true;
00058 }