|
642.1.10
by Lee
move functions from item.cc/item.h to item directory |
1 |
/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
|
2 |
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
|
|
3 |
*
|
|
4 |
* Copyright (C) 2008 Sun Microsystems
|
|
5 |
*
|
|
6 |
* This program is free software; you can redistribute it and/or modify
|
|
7 |
* it under the terms of the GNU General Public License as published by
|
|
8 |
* the Free Software Foundation; version 2 of the License.
|
|
9 |
*
|
|
10 |
* This program is distributed in the hope that it will be useful,
|
|
11 |
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
12 |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
13 |
* GNU General Public License for more details.
|
|
14 |
*
|
|
15 |
* You should have received a copy of the GNU General Public License
|
|
16 |
* along with this program; if not, write to the Free Software
|
|
17 |
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
18 |
*/
|
|
19 |
||
20 |
#ifndef DRIZZLED_ITEM_REF_NULL_HELPER_H
|
|
21 |
#define DRIZZLED_ITEM_REF_NULL_HELPER_H
|
|
22 |
||
23 |
/*
|
|
24 |
An object of this class:
|
|
25 |
- Converts val_XXX() calls to ref->val_XXX_result() calls, like Item_ref.
|
|
26 |
- Sets owner->was_null=true if it has returned a NULL value from any
|
|
27 |
val_XXX() function. This allows to inject an Item_ref_null_helper
|
|
28 |
object into subquery and then check if the subquery has produced a row
|
|
29 |
with NULL value.
|
|
30 |
*/
|
|
31 |
||
32 |
class Item_ref_null_helper: public Item_ref |
|
33 |
{
|
|
34 |
protected: |
|
35 |
Item_in_subselect* owner; |
|
36 |
public: |
|
37 |
Item_ref_null_helper(Name_resolution_context *context_arg, |
|
38 |
Item_in_subselect* master, Item **item, |
|
39 |
const char *table_name_arg, const char *field_name_arg) |
|
40 |
:Item_ref(context_arg, item, table_name_arg, field_name_arg), |
|
41 |
owner(master) {} |
|
42 |
double val_real(); |
|
43 |
int64_t val_int(); |
|
44 |
String* val_str(String* s); |
|
45 |
my_decimal *val_decimal(my_decimal *); |
|
46 |
bool val_bool(); |
|
47 |
bool get_date(DRIZZLE_TIME *ltime, uint32_t fuzzydate); |
|
48 |
virtual void print(String *str, enum_query_type query_type); |
|
49 |
/*
|
|
50 |
we add RAND_TABLE_BIT to prevent moving this item from HAVING to WHERE
|
|
51 |
*/
|
|
52 |
table_map used_tables() const |
|
53 |
{
|
|
54 |
return (depended_from ? |
|
55 |
OUTER_REF_TABLE_BIT : |
|
56 |
(*ref)->used_tables() | RAND_TABLE_BIT); |
|
57 |
}
|
|
58 |
};
|
|
59 |
||
60 |
#endif /* DRIZZLED_ITEM_REF_NULL_HELPER_H */ |