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Bug#50995 Having clause on subquery result produces incorrect results.

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The problem is that cond->fix_fields(thd, 0) breaks
condition(cuts off 'having'). The reason of that is
that NULL valued Item pointer is present in the
middle of Item list and it breaks the Item processing
loop.
This commit is contained in:
Sergey Glukhov 2010-02-26 15:39:25 +04:00
parent 79d8de67a9
commit fe94dec679
4 changed files with 66 additions and 6 deletions
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20
mysql-test/r/having.result
View File

@ -430,4 +430,24 @@ SELECT b, COUNT(DISTINCT a) FROM t1 GROUP BY b HAVING b is NULL;
b COUNT(DISTINCT a)
NULL 1
DROP TABLE t1;
#
# Bug#50995 Having clause on subquery result produces incorrect results.
#
CREATE TABLE t1
(
id1 INT,
id2 INT NOT NULL,
INDEX id1(id2)
);
INSERT INTO t1 SET id1=1, id2=1;
INSERT INTO t1 SET id1=2, id2=1;
INSERT INTO t1 SET id1=3, id2=1;
SELECT t1.id1,
(SELECT 0 FROM DUAL
WHERE t1.id1=t1.id1) AS amount FROM t1
WHERE t1.id2 = 1
HAVING amount > 0
ORDER BY t1.id1;
id1 amount
DROP TABLE t1;
End of 5.0 tests

26
mysql-test/t/having.test
View File

@ -442,4 +442,30 @@ INSERT INTO t1 VALUES (1, 1), (2,2), (3, NULL);
SELECT b, COUNT(DISTINCT a) FROM t1 GROUP BY b HAVING b is NULL;
DROP TABLE t1;
--echo #
--echo # Bug#50995 Having clause on subquery result produces incorrect results.
--echo #
CREATE TABLE t1
(
id1 INT,
id2 INT NOT NULL,
INDEX id1(id2)
);
INSERT INTO t1 SET id1=1, id2=1;
INSERT INTO t1 SET id1=2, id2=1;
INSERT INTO t1 SET id1=3, id2=1;
SELECT t1.id1,
(SELECT 0 FROM DUAL
WHERE t1.id1=t1.id1) AS amount FROM t1
WHERE t1.id2 = 1
HAVING amount > 0
ORDER BY t1.id1;
DROP TABLE t1;
--echo End of 5.0 tests

18
sql/item_cmpfunc.h
View File

@ -1474,9 +1474,21 @@ public:
Item_cond(THD *thd, Item_cond *item);
Item_cond(List<Item> &nlist)
:Item_bool_func(), list(nlist), abort_on_null(0) {}
bool add(Item *item) { return list.push_back(item); }
bool add_at_head(Item *item) { return list.push_front(item); }
void add_at_head(List<Item> *nlist) { list.prepand(nlist); }
bool add(Item *item)
{
DBUG_ASSERT(item);
return list.push_back(item);
}
bool add_at_head(Item *item)
{
DBUG_ASSERT(item);
return list.push_front(item);
}
void add_at_head(List<Item> *nlist)
{
DBUG_ASSERT(nlist->elements);
list.prepand(nlist);
}
bool fix_fields(THD *, Item **ref);
enum Type type() const { return COND_ITEM; }

8
sql/sql_select.cc
View File

@ -8200,7 +8200,8 @@ static Item *eliminate_item_equal(COND *cond, COND_EQUAL *upper_levels,
else
{
DBUG_ASSERT(cond->type() == Item::COND_ITEM);
((Item_cond *) cond)->add_at_head(&eq_list);
if (eq_list.elements)
((Item_cond *) cond)->add_at_head(&eq_list);
}
cond->quick_fix_field();
@ -15657,7 +15658,7 @@ static bool add_ref_to_table_cond(THD *thd, JOIN_TAB *join_tab)
Item_cond_and *cond=new Item_cond_and();
TABLE *table=join_tab->table;
int error;
int error= 0;
if (!cond)
DBUG_RETURN(TRUE);
@ -15675,7 +15676,8 @@ static bool add_ref_to_table_cond(THD *thd, JOIN_TAB *join_tab)
cond->fix_fields(thd, (Item**)&cond);
if (join_tab->select)
{
error=(int) cond->add(join_tab->select->cond);
if (join_tab->select->cond)
error=(int) cond->add(join_tab->select->cond);
join_tab->select_cond=join_tab->select->cond=cond;
}
else if ((join_tab->select= make_select(join_tab->table, 0, 0, cond, 0,