Drizzled Public API Documentation

natural_join_column.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/memory/sql_alloc.h>
00023 
00024 namespace drizzled
00025 {
00026 
00027 class Field;
00028 class TableList;
00029 class Item;
00030 
00031 /*
00032   Column reference of a NATURAL/USING join. Since column references in
00033   joins can be both from views and stored tables, may point to either a
00034   Field (for tables).
00035 */
00036 
00037 class Natural_join_column: public memory::SqlAlloc
00038 {
00039 public:
00040   Field            *table_field; /* Column reference of table or temp view. */
00041   TableList *table_ref; /* Original base table/view reference. */
00042   /*
00043     True if a common join column of two NATURAL/USING join operands. Notice
00044     that when we have a hierarchy of nested NATURAL/USING joins, a column can
00045     be common at some level of nesting but it may not be common at higher
00046     levels of nesting. Thus this flag may change depending on at which level
00047     we are looking at some column.
00048   */
00049   bool is_common;
00050 public:
00051   Natural_join_column(Field *field_param, TableList *tab);
00052   const char *name();
00053   Item *create_item(Session *session);
00054   Field *field();
00055   const char *table_name();
00056   const char *db_name();
00057 };
00058 
00059 } /* namespace drizzled */
00060