Commit b671815c authored by unknown's avatar unknown
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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

mysql-test/r/subselect.result

+2 −2
Original line number Diff line number Diff line
@@ -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

+84 −6
Original line number Diff line number Diff line
@@ -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

+69 −2
Original line number Diff line number Diff line
@@ -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

+25 −14
Original line number Diff line number Diff line
@@ -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