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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
*/
#ifndef DRIZZLED_ITEM_OUTER_REF_H
#define DRIZZLED_ITEM_OUTER_REF_H
#include <drizzled/item/ref.h>
#include <drizzled/item/direct_ref.h>
#include <drizzled/item/field.h>
/*
Class for outer fields.
An object of this class is created when the select where the outer field was
resolved is a grouping one. After it has been fixed the ref field will point
to either an Item_ref or an Item_direct_ref object which will be used to
access the field.
See also comments for the fix_inner_refs() and the
Item_field::fix_outer_field() functions.
*/
namespace drizzled
{
class Item_outer_ref :public Item_direct_ref
{
public:
Item *outer_ref;
/* The aggregate function under which this outer ref is used, if any. */
Item_sum *in_sum_func;
/*
true <=> that the outer_ref is already present in the select list
of the outer select.
*/
bool found_in_select_list;
Item_outer_ref(Name_resolution_context *context_arg,
Item_field *outer_field_arg)
:Item_direct_ref(context_arg, 0, outer_field_arg->table_name,
outer_field_arg->field_name),
outer_ref(outer_field_arg), in_sum_func(0),
found_in_select_list(0)
{
ref= &outer_ref;
set_properties();
fixed= 0;
}
Item_outer_ref(Name_resolution_context *context_arg, Item **item,
const char *table_name_arg, const char *field_name_arg,
bool alias_name_used_arg)
:Item_direct_ref(context_arg, item, table_name_arg, field_name_arg,
alias_name_used_arg),
outer_ref(0), in_sum_func(0), found_in_select_list(1)
{}
void save_in_result_field(bool)
{
outer_ref->save_org_in_field(result_field);
}
bool fix_fields(Session *, Item **);
void fix_after_pullout(Select_Lex *new_parent, Item **ref);
table_map used_tables() const
{
return (*ref)->const_item() ? 0 : OUTER_REF_TABLE_BIT;
}
virtual Ref_Type ref_type() { return OUTER_REF; }
};
} /* namespace drizzled */
#endif /* DRIZZLED_ITEM_OUTER_REF_H */
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