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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2008 Sun Microsystems, Inc.
*
* 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
*/
#pragma once
#include <drizzled/item/field.h>
namespace drizzled {
/*
Item_insert_value -- an implementation of VALUES() function.
You can use the VALUES(col_name) function in the UPDATE clause
to refer to column values from the INSERT portion of the INSERT
... UPDATE statement. In other words, VALUES(col_name) in the
UPDATE clause refers to the value of col_name that would be
inserted, had no duplicate-key conflict occurred.
In all other places this function returns NULL.
*/
class Item_insert_value : public Item_field
{
public:
Item *arg;
Item_insert_value(Name_resolution_context *context_arg, Item *a)
: Item_field(context_arg, NULL, NULL, NULL),
arg(a) {}
bool eq(const Item *item, bool binary_cmp) const;
bool fix_fields(Session *, Item **);
virtual void print(String *str);
int save_in_field(Field *field_arg, bool no_conversions)
{
return Item_field::save_in_field(field_arg, no_conversions);
}
/*
We use RAND_TABLE_BIT to prevent Item_insert_value from
being treated as a constant and precalculated before execution
*/
table_map used_tables() const { return RAND_TABLE_BIT; }
bool walk(Item_processor processor, bool walk_subquery, unsigned char *args)
{
return arg->walk(processor, walk_subquery, args) || (this->*processor)(args);
}
};
} /* namespace drizzled */
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