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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)
This commit is contained in:
unknown
2007-01-12 22:11:40 +03:00
parent 6943153ead
commit b671815c95
4 changed files with 180 additions and 24 deletions

View File

@ -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;