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BUG#24085: Wrong result for NULL IN (SELECT not_null_val FROM ...) 

When transforming "oe IN (SELECT ie ...)" wrap the pushed-down predicates
iff "oe can be null", not "ie can be null".
The fix doesn't cover row-based subqueries, those will be fixed in #24127.


mysql-test/r/subselect.result:
  BUG#24085: Wrong result for NULL IN (SELECT not_null_val FROM ...)
  Update the test results (checked)
mysql-test/r/subselect3.result:
  BUG#24085: Wrong result for NULL IN (SELECT not_null_val FROM ...)
  - Testcase
mysql-test/t/subselect3.test:
  BUG#24085: Wrong result for NULL IN (SELECT not_null_val FROM ...)
  - Testcase
sql/item_subselect.cc:
  BUG#24085: Wrong result for NULL IN (SELECT not_null_val FROM ...)
  When transforming "oe IN (SELECT ie ...)" we should make special 
  provisions (wrap the pushed predicates) if we can encounter 
  NULL IN (SELECT ...), i.e. when oe->maybe_null. The code was checking
  for ie->maybe_null instead, fixed it for single value based subqueries.
  
  Row-based subqueries (e.g. (a,b) IN (SELECT c,d ...)) are not fixed 
  because they won't produce correct results for several other reasons 
  (filed as #24085)
parent 6943153e
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Showing with 180 additions and 24 deletions
mysql-test/r/subselect.result
View file @ b671815c
......@@ -744,7 +744,7 @@ id select_type table type possible_keys key key_len ref rows Extra
3 DEPENDENT UNION NULL NULL NULL NULL NULL NULL NULL No tables used
NULL UNION RESULT <union2,3> ALL NULL NULL NULL NULL NULL
Warnings:
Note 1003 select `test`.`t2`.`id` AS `id` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`id`,<exists>(select 1 AS `1` having trigcond((<cache>(`test`.`t2`.`id`) = <ref_null_helper>(1))) union select 3 AS `3` having trigcond((<cache>(`test`.`t2`.`id`) = <ref_null_helper>(3)))))
Note 1003 select `test`.`t2`.`id` AS `id` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`id`,<exists>(select 1 AS `1` having (<cache>(`test`.`t2`.`id`) = <ref_null_helper>(1)) union select 3 AS `3` having (<cache>(`test`.`t2`.`id`) = <ref_null_helper>(3))))
SELECT * FROM t2 WHERE id IN (SELECT 5 UNION SELECT 3);
id
SELECT * FROM t2 WHERE id IN (SELECT 5 UNION SELECT 2);
......@@ -907,7 +907,7 @@ id select_type table type possible_keys key key_len ref rows Extra
2 DEPENDENT SUBQUERY t2 ref_or_null a a 5 func 2 Using where; Using index
2 DEPENDENT SUBQUERY t3 ALL NULL NULL NULL NULL 3 Using where
Warnings:
Note 1003 select `test`.`t1`.`a` AS `a`,<in_optimizer>(`test`.`t1`.`a`,<exists>(select 1 AS `Not_used` from `test`.`t2` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t2`.`a`) and trigcond(((<cache>(`test`.`t1`.`a`) = `test`.`t2`.`a`) or isnull(`test`.`t2`.`a`)))) having trigcond(<is_not_null_test>(`test`.`t2`.`a`)))) AS `t1.a in (select t2.a from t2,t3 where t3.a=t2.a)` from `test`.`t1`
Note 1003 select `test`.`t1`.`a` AS `a`,<in_optimizer>(`test`.`t1`.`a`,<exists>(select 1 AS `Not_used` from `test`.`t2` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t2`.`a`) and ((<cache>(`test`.`t1`.`a`) = `test`.`t2`.`a`) or isnull(`test`.`t2`.`a`))) having <is_not_null_test>(`test`.`t2`.`a`))) AS `t1.a in (select t2.a from t2,t3 where t3.a=t2.a)` from `test`.`t1`
drop table t1,t2,t3;
create table t1 (a float);
select 10.5 IN (SELECT * from t1 LIMIT 1);
......
mysql-test/r/subselect3.result
View file @ b671815c
......@@ -15,9 +15,8 @@ insert into t2 values
(4, NULL),
(2, NULL);
select a, oref, a in (select max(ie)
from t1 where oref=t2.oref group by grp) from t2;
a oref a in (select max(ie)
from t1 where oref=t2.oref group by grp)
from t1 where oref=t2.oref group by grp) Z from t2;
a oref Z
1 1 1
2 2 0
3 3 NULL
......@@ -25,14 +24,13 @@ NULL 4 0
NULL 2 NULL
explain extended
select a, oref, a in (select max(ie)
from t1 where oref=t2.oref group by grp) from t2;
from t1 where oref=t2.oref group by grp) Z from t2;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 5
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 6 Using where; Using temporary; Using filesort
Warnings:
Note 1276 Field or reference 't2.oref' of SELECT #2 was resolved in SELECT #1
Note 1003 select `test`.`t2`.`a` AS `a`,`test`.`t2`.`oref` AS `oref`,<in_optimizer>(`test`.`t2`.`a`,<exists>(select max(`test`.`t1`.`ie`) AS `max(ie)` from `test`.`t1` where (`test`.`t1`.`oref` = `test`.`t2`.`oref`) group by `test`.`t1`.`grp` having trigcond((<cache>(`test`.`t2`.`a`) = <ref_null_helper>(max(`test`.`t1`.`ie`)))))) AS `a in (select max(ie)
from t1 where oref=t2.oref group by grp)` from `test`.`t2`
Note 1003 select `test`.`t2`.`a` AS `a`,`test`.`t2`.`oref` AS `oref`,<in_optimizer>(`test`.`t2`.`a`,<exists>(select max(`test`.`t1`.`ie`) AS `max(ie)` from `test`.`t1` where (`test`.`t1`.`oref` = `test`.`t2`.`oref`) group by `test`.`t1`.`grp` having trigcond((<cache>(`test`.`t2`.`a`) = <ref_null_helper>(max(`test`.`t1`.`ie`)))))) AS `Z` from `test`.`t2`
explain extended
select a, oref from t2
where a in (select max(ie) from t1 where oref=t2.oref group by grp);
......@@ -42,6 +40,16 @@ id select_type table type possible_keys key key_len ref rows Extra
Warnings:
Note 1276 Field or reference 't2.oref' of SELECT #2 was resolved in SELECT #1
Note 1003 select `test`.`t2`.`a` AS `a`,`test`.`t2`.`oref` AS `oref` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(select max(`test`.`t1`.`ie`) AS `max(ie)` from `test`.`t1` where (`test`.`t1`.`oref` = `test`.`t2`.`oref`) group by `test`.`t1`.`grp` having (<cache>(`test`.`t2`.`a`) = <ref_null_helper>(max(`test`.`t1`.`ie`)))))
select a, oref, a in (
select max(ie) from t1 where oref=t2.oref group by grp union
select max(ie) from t1 where oref=t2.oref group by grp
) Z from t2;
a oref Z
1 1 1
2 2 0
3 3 NULL
NULL 4 0
NULL 2 NULL
create table t3 (a int);
insert into t3 values (NULL), (NULL);
flush status;
......@@ -151,3 +159,73 @@ Warnings:
Note 1276 Field or reference 't3.oref' of SELECT #2 was resolved in SELECT #1
Note 1003 select `test`.`t3`.`a` AS `a`,`test`.`t3`.`oref` AS `oref`,<in_optimizer>(`test`.`t3`.`a`,<exists>(select 1 AS `Not_used` from `test`.`t1` join `test`.`t2` where ((`test`.`t2`.`a` = `test`.`t1`.`b`) and (`test`.`t2`.`b` = `test`.`t3`.`oref`) and trigcond(((<cache>(`test`.`t3`.`a`) = `test`.`t1`.`a`) or isnull(`test`.`t1`.`a`)))) having trigcond(<is_not_null_test>(`test`.`t1`.`a`)))) AS `Z` from `test`.`t3`
drop table t1, t2, t3;
create table t1 (a int NOT NULL, b int NOT NULL, key(a));
insert into t1 values
(0,0),(1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
create table t2 like t1;
insert into t2 select * from t1;
update t2 set b=1;
create table t3 (a int, oref int);
insert into t3 values (1, 1), (NULL,1), (NULL,0);
select a, oref,
t3.a in (select t1.a from t1, t2 where t1.b=t2.a and t2.b=t3.oref) Z
from t3;
a oref Z
1 1 1
NULL 1 NULL
NULL 0 0
This must show a trig_cond:
explain extended
select a, oref,
t3.a in (select t1.a from t1, t2 where t1.b=t2.a and t2.b=t3.oref) Z
from t3;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t3 ALL NULL NULL NULL NULL 3
2 DEPENDENT SUBQUERY t1 ref a a 4 func 2 Using where
2 DEPENDENT SUBQUERY t2 ref a a 4 test.t1.b 1 Using where
Warnings:
Note 1276 Field or reference 't3.oref' of SELECT #2 was resolved in SELECT #1
Note 1003 select `test`.`t3`.`a` AS `a`,`test`.`t3`.`oref` AS `oref`,<in_optimizer>(`test`.`t3`.`a`,<exists>(select 1 AS `Not_used` from `test`.`t1` join `test`.`t2` where ((`test`.`t2`.`a` = `test`.`t1`.`b`) and (`test`.`t2`.`b` = `test`.`t3`.`oref`) and trigcond((<cache>(`test`.`t3`.`a`) = `test`.`t1`.`a`))))) AS `Z` from `test`.`t3`
drop table t1,t2,t3;
create table t1 (oref int, grp int);
insert into t1 (oref, grp) values
(1, 1),
(1, 1);
create table t2 (oref int, a int);
insert into t2 values
(1, NULL),
(2, NULL);
select a, oref,
a in (select count(*) from t1 group by grp having grp=t2.oref) Z from t2;
a oref Z
NULL 1 NULL
NULL 2 0
This must show a trig_cond:
explain extended
select a, oref,
a in (select count(*) from t1 group by grp having grp=t2.oref) Z from t2;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 2
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 2 Using temporary; Using filesort
Warnings:
Note 1276 Field or reference 't2.oref' of SELECT #2 was resolved in SELECT #1
Note 1003 select `test`.`t2`.`a` AS `a`,`test`.`t2`.`oref` AS `oref`,<in_optimizer>(`test`.`t2`.`a`,<exists>(select count(0) AS `count(*)` from `test`.`t1` group by `test`.`t1`.`grp` having ((`test`.`t1`.`grp` = `test`.`t2`.`oref`) and trigcond((<cache>(`test`.`t2`.`a`) = <ref_null_helper>(count(0))))))) AS `Z` from `test`.`t2`
drop table t1, t2;
create table t1 (a int, b int, primary key (a));
insert into t1 values (1,1), (3,1),(100,1);
create table t2 (a int, b int);
insert into t2 values (1,1),(2,1),(NULL,1),(NULL,0);
select a,b, a in (select a from t1 where t1.b = t2.b union select a from
t1 where t1.b = t2.b) Z from t2 ;
a b Z
1 1 1
2 1 0
NULL 1 NULL
NULL 0 0
select a,b, a in (select a from t1 where t1.b = t2.b) Z from t2 ;
a b Z
1 1 1
2 1 0
NULL 1 NULL
NULL 0 0
drop table t1, t2;
mysql-test/t/subselect3.test
View file @ b671815c
......@@ -34,18 +34,22 @@ insert into t2 values
# true, false, null, false, null
select a, oref, a in (select max(ie)
from t1 where oref=t2.oref group by grp) from t2;
from t1 where oref=t2.oref group by grp) Z from t2;
# This must have a trigcond
explain extended
select a, oref, a in (select max(ie)
from t1 where oref=t2.oref group by grp) from t2;
from t1 where oref=t2.oref group by grp) Z from t2;
# This must not have a trigcond:
explain extended
select a, oref from t2
where a in (select max(ie) from t1 where oref=t2.oref group by grp);
select a, oref, a in (
select max(ie) from t1 where oref=t2.oref group by grp union
select max(ie) from t1 where oref=t2.oref group by grp
) Z from t2;
# Non-correlated subquery, 2 NULL evaluations
create table t3 (a int);
......@@ -135,3 +139,66 @@ from t3;
drop table t1, t2, t3;
#
# BUG#24085
#
# case 1: NULL IN (SELECT not_null_val FROM ...) w/o HAVING/GROUP-BY/etc
create table t1 (a int NOT NULL, b int NOT NULL, key(a));
insert into t1 values
(0,0),(1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
create table t2 like t1;
insert into t2 select * from t1;
update t2 set b=1;
create table t3 (a int, oref int);
insert into t3 values (1, 1), (NULL,1), (NULL,0);
select a, oref,
t3.a in (select t1.a from t1, t2 where t1.b=t2.a and t2.b=t3.oref) Z
from t3;
--echo This must show a trig_cond:
explain extended
select a, oref,
t3.a in (select t1.a from t1, t2 where t1.b=t2.a and t2.b=t3.oref) Z
from t3;
drop table t1,t2,t3;
# case 2: NULL IN (SELECT not_null_val FROM) where SELECT has GROUP BY
create table t1 (oref int, grp int);
insert into t1 (oref, grp) values
(1, 1),
(1, 1);
# Ok, for
# select count(*) from t1 group by grp having grp=$PARAM$
# we'll have:
# 1 -> (2)
# 2 -> () - nothing
create table t2 (oref int, a int);
insert into t2 values
(1, NULL),
(2, NULL);
select a, oref,
a in (select count(*) from t1 group by grp having grp=t2.oref) Z from t2;
--echo This must show a trig_cond:
explain extended
select a, oref,
a in (select count(*) from t1 group by grp having grp=t2.oref) Z from t2;
drop table t1, t2;
create table t1 (a int, b int, primary key (a));
insert into t1 values (1,1), (3,1),(100,1);
create table t2 (a int, b int);
insert into t2 values (1,1),(2,1),(NULL,1),(NULL,0);
select a,b, a in (select a from t1 where t1.b = t2.b union select a from
t1 where t1.b = t2.b) Z from t2 ;
select a,b, a in (select a from t1 where t1.b = t2.b) Z from t2 ;
drop table t1, t2;
sql/item_subselect.cc
View file @ b671815c
......@@ -922,7 +922,7 @@ Item_in_subselect::single_value_transformer(JOIN *join,
if (!substitution)
{
//first call for this unit
/* We're invoked for the 1st (or the only) SELECT in the subquery UNION */
SELECT_LEX_UNIT *unit= select_lex->master_unit();
substitution= optimizer;
......@@ -972,7 +972,7 @@ Item_in_subselect::single_value_transformer(JOIN *join,
ref_pointer_array,
(char *)"<ref>",
this->full_name()));
if (!abort_on_null && ((Item*)select_lex->item_list.head())->maybe_null)
if (!abort_on_null && left_expr->maybe_null)
{
/*
We can encounter "NULL IN (SELECT ...)". Wrap the added condition
......@@ -1013,9 +1013,13 @@ Item_in_subselect::single_value_transformer(JOIN *join,
item= func->create(expr, item);
if (!abort_on_null && orig_item->maybe_null)
{
having=
new Item_func_trig_cond(new Item_is_not_null_test(this, having),
&enable_pushed_conds);
having= new Item_is_not_null_test(this, having);
if (left_expr->maybe_null)
{
if (!(having= new Item_func_trig_cond(having,
&enable_pushed_conds)))
DBUG_RETURN(RES_ERROR);
}
/*
Item_is_not_null_test can't be changed during fix_fields()
we can assign select_lex->having here, and pass 0 as last
......@@ -1032,16 +1036,19 @@ Item_in_subselect::single_value_transformer(JOIN *join,
select_lex->having_fix_field= 0;
if (tmp)
DBUG_RETURN(RES_ERROR);
/*
NOTE: It is important that we add this "IS NULL" here, even when
orig_item can't be NULL. This is needed so that this predicate is
only used by ref[_or_null] analyzer (and, e.g. is not used by const
propagation).
*/
item= new Item_cond_or(item,
new Item_func_isnull(orig_item));
item= new Item_func_trig_cond(item, &enable_pushed_conds);
}
/*
If we may encounter NULL IN (SELECT ...) and care between NULL and
FALSE, wrap it in a trigger.
*/
if (!abort_on_null && left_expr->maybe_null)
{
if (!(item= new Item_func_trig_cond(item, &enable_pushed_conds)))
DBUG_RETURN(RES_ERROR);
}
item->name= (char *)in_additional_cond;
/*
AND can't be changed during fix_fields()
......@@ -1073,9 +1080,13 @@ Item_in_subselect::single_value_transformer(JOIN *join,
select_lex->ref_pointer_array,
(char *)"<no matter>",
(char *)"<result>"));
new_having= new Item_func_trig_cond(new_having, &enable_pushed_conds);
if (!abort_on_null && left_expr->maybe_null)
{
if (!(new_having= new Item_func_trig_cond(new_having,
&enable_pushed_conds)))
DBUG_RETURN(RES_ERROR);
}
select_lex->having= join->having= new_having;
select_lex->having_fix_field= 1;
/*
we do not check join->having->fixed, because comparison function
......
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