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Bug#23800: Outer fields in correlated subqueries is used in a temporary table 

created for sorting.

Any outer reference in a subquery was represented by an Item_field object.
If the outer select employs a temporary table all such fields should be
replaced with fields from that temporary table in order to point to the 
actual data. This replacement wasn't done and that resulted in a wrong
subquery evaluation and a wrong result of the whole query.

Now any outer field is represented by two objects - Item_field placed in the
outer select and Item_outer_ref in the subquery. Item_field object is
processed as a normal field and the reference to it is saved in the
ref_pointer_array. Thus the Item_outer_ref is always references the correct
field. The original field is substituted for a reference in the
Item_field::fix_outer_field() function.

New function called fix_inner_refs() is added to fix fields referenced from
inner selects and to fix references (Item_ref objects) to these fields.

The new Item_outer_ref class is a descendant of the Item_direct_ref class.
It additionally stores a reference to the original field and designed to
behave more like a field.


sql/item.cc:
  Bug#23800: Correlated sub query returning incorrect results when operated upon.
  Now all outer fields are substituted with references to them (Item_outer_ref objects)
  in the Item_field::fix_outer_field() function.
  The original field is saved in the Item_outer_ref object.
sql/item.h:
  Bug#23800: Correlated sub query returning incorrect results when operated upon.
  Added the Item_outer_ref class.
sql/mysql_priv.h:
  Bug#23800: Correlated sub query returning incorrect results when operated upon.
  Added the fix_inner_refs() function prototype.
sql/sql_delete.cc:
  Bug#23800: Correlated sub query returning incorrect results when operated upon.
  Added call to the fix_inner_refs() function.
sql/sql_select.cc:
  Bug#23800: Correlated sub query returning incorrect results when operated upon.
  The new function called fix_inner_refs() is added.
mysql-test/r/subselect.result:
  Added a test case for bug#23800: Correlated sub query returning incorrect results when
  operated upon.
sql/sql_update.cc:
  Bug#23800: Correlated sub query returning incorrect results when operated upon.
  Added call to the fix_inner_refs() function.
mysql-test/r/subselect3.result:
  Corrected test cases result after fix for bug#23800: Correlated sub query returning
  incorrect results when operated upon.
mysql-test/t/subselect.test:
  Added a test case for bug#23800: Correlated sub query returning incorrect results when
  operated upon.
sql/sql_lex.cc:
  Bug#23800: Correlated sub query returning incorrect results when operated upon.
  Added cleanup of the inner_refs_list.
sql/sql_lex.h:
  Bug#23800: Correlated sub query returning incorrect results when operated upon.
  The inner_refs_list is added to the SELECT_LEX class.
parent 9f1c12ac
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mysql-test/r/subselect.result
View file @ 4410c83f
......@@ -224,7 +224,7 @@ id select_type table type possible_keys key key_len ref rows Extra
2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 2
3 DEPENDENT SUBQUERY t3 ALL NULL NULL NULL NULL 3 Using where
Warnings:
Note 1276 Field or reference 't4.a' of SELECT #3 was resolved in SELECT #1
Note 1276 Field or reference 'test.t4.a' of SELECT #3 was resolved in SELECT #1
Note 1003 select `test`.`t4`.`b` AS `b`,(select avg((`test`.`t2`.`a` + (select min(`test`.`t3`.`a`) AS `min(t3.a)` from `test`.`t3` where (`test`.`t3`.`a` >= `test`.`t4`.`a`)))) AS `avg(t2.a+(select min(t3.a) from t3 where t3.a >= t4.a))` from `test`.`t2`) AS `(select avg(t2.a+(select min(t3.a) from t3 where t3.a >= t4.a)) from t2)` from `test`.`t4`
select * from t3 where exists (select * from t2 where t2.b=t3.a);
a
......@@ -313,8 +313,8 @@ id select_type table type possible_keys key key_len ref rows Extra
3 DEPENDENT UNION t5 ALL NULL NULL NULL NULL 2 Using where
NULL UNION RESULT <union2,3> ALL NULL NULL NULL NULL NULL
Warnings:
Note 1276 Field or reference 't2.a' of SELECT #2 was resolved in SELECT #1
Note 1276 Field or reference 't2.a' of SELECT #3 was resolved in SELECT #1
Note 1276 Field or reference 'test.t2.a' of SELECT #2 was resolved in SELECT #1
Note 1276 Field or reference 'test.t2.a' of SELECT #3 was resolved in SELECT #1
Note 1003 select (select `test`.`t1`.`a` AS `a` from `test`.`t1` where (`test`.`t1`.`a` = `test`.`t2`.`a`) union select `test`.`t5`.`a` AS `a` from `test`.`t5` where (`test`.`t5`.`a` = `test`.`t2`.`a`)) AS `(select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a)`,`test`.`t2`.`a` AS `a` from `test`.`t2`
select (select a from t1 where t1.a=t2.a union all select a from t5 where t5.a=t2.a), a from t2;
ERROR 21000: Subquery returns more than 1 row
......@@ -330,9 +330,9 @@ patient_uq clinic_uq
explain extended select * from t6 where exists (select * from t7 where uq = clinic_uq);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t6 ALL NULL NULL NULL NULL 4 Using where
2 DEPENDENT SUBQUERY t7 eq_ref PRIMARY PRIMARY 4 test.t6.clinic_uq 1 Using index
2 DEPENDENT SUBQUERY t7 eq_ref PRIMARY PRIMARY 4 t6.clinic_uq 1 Using where; Using index
Warnings:
Note 1276 Field or reference 'clinic_uq' of SELECT #2 was resolved in SELECT #1
Note 1276 Field or reference 'test.t6.clinic_uq' of SELECT #2 was resolved in SELECT #1
Note 1003 select `test`.`t6`.`patient_uq` AS `patient_uq`,`test`.`t6`.`clinic_uq` AS `clinic_uq` from `test`.`t6` where exists(select 1 AS `Not_used` from `test`.`t7` where (`test`.`t7`.`uq` = `test`.`t6`.`clinic_uq`))
select * from t1 where a= (select a from t2,t4 where t2.b=t4.b);
ERROR 23000: Column 'a' in field list is ambiguous
......@@ -868,7 +868,7 @@ explain extended select (select a+1) from t1;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 ALL NULL NULL NULL NULL 3
Warnings:
Note 1276 Field or reference 'a' of SELECT #2 was resolved in SELECT #1
Note 1276 Field or reference 'test.t1.a' of SELECT #2 was resolved in SELECT #1
Note 1249 Select 2 was reduced during optimization
Note 1003 select (`test`.`t1`.`a` + 1) AS `(select a+1)` from `test`.`t1`
select (select a+1) from t1;
......@@ -1741,9 +1741,9 @@ Note 1003 select `test`.`t1`.`id` AS `id`,`test`.`t1`.`text` AS `text` from `tes
explain extended select * from t1 as tt where not exists (select id from t1 where id < 8 and (id = tt.id or id is null) having id is not null);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY tt ALL NULL NULL NULL NULL 12 Using where
2 DEPENDENT SUBQUERY t1 eq_ref PRIMARY PRIMARY 4 test.tt.id 1 Using where; Using index
2 DEPENDENT SUBQUERY t1 eq_ref PRIMARY PRIMARY 4 tt.id 1 Using where; Using index
Warnings:
Note 1276 Field or reference 'tt.id' of SELECT #2 was resolved in SELECT #1
Note 1276 Field or reference 'test.tt.id' of SELECT #2 was resolved in SELECT #1
Note 1003 select `test`.`tt`.`id` AS `id`,`test`.`tt`.`text` AS `text` from `test`.`t1` `tt` where (not(exists(select `test`.`t1`.`id` AS `id` from `test`.`t1` where ((`test`.`t1`.`id` < 8) and (`test`.`t1`.`id` = `test`.`tt`.`id`)) having (`test`.`t1`.`id` is not null))))
insert into t1 (id, text) values (1000, 'text1000'), (1001, 'text1001');
create table t2 (id int not null, text varchar(20) not null default '', primary key (id));
......@@ -2279,7 +2279,7 @@ id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY up ALL NULL NULL NULL NULL 2 Using where
2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 2 Using where
Warnings:
Note 1276 Field or reference 'up.a' of SELECT #2 was resolved in SELECT #1
Note 1276 Field or reference 'test.up.a' of SELECT #2 was resolved in SELECT #1
Note 1003 select `test`.`up`.`a` AS `a`,`test`.`up`.`b` AS `b` from `test`.`t1` `up` where exists(select 1 AS `Not_used` from `test`.`t1` where (`test`.`t1`.`a` = `test`.`up`.`a`))
drop table t1;
CREATE TABLE t1 (t1_a int);
......@@ -3712,3 +3712,45 @@ bb 2
cc 3
dd 1
DROP TABLE t1,t2,t3;
CREATE TABLE t1(f1 int);
CREATE TABLE t2(f2 int, f21 int, f3 timestamp);
INSERT INTO t1 VALUES (1),(1),(2),(2);
INSERT INTO t2 VALUES (1,1,"2004-02-29 11:11:11"), (2,2,"2004-02-29 11:11:11");
SELECT ((SELECT f2 FROM t2 WHERE f21=f1 LIMIT 1) * COUNT(f1)) AS sq FROM t1 GROUP BY f1;
sq
2
4
SELECT (SELECT SUM(1) FROM t2 ttt GROUP BY t2.f3 LIMIT 1) AS tt FROM t2;
tt
2
2
PREPARE stmt1 FROM 'SELECT ((SELECT f2 FROM t2 WHERE f21=f1 LIMIT 1) * COUNT(f1)) AS sq FROM t1 GROUP BY f1';
EXECUTE stmt1;
sq
2
4
EXECUTE stmt1;
sq
2
4
DEALLOCATE PREPARE stmt1;
SELECT f2, AVG(f21),
(SELECT t.f3 FROM t2 AS t WHERE t2.f2=t.f2 AND t.f3=MAX(t2.f3)) AS test
FROM t2 GROUP BY f2;
f2 AVG(f21) test
1 1.0000 2004-02-29 11:11:11
2 2.0000 2004-02-29 11:11:11
DROP TABLE t1,t2;
CREATE TABLE t1 (a int, b INT, c CHAR(10) NOT NULL);
INSERT INTO t1 VALUES
(1,1,'a'), (1,2,'b'), (1,3,'c'), (1,4,'d'), (1,5,'e'),
(2,1,'f'), (2,2,'g'), (2,3,'h'), (3,4,'i'), (3,3,'j'),
(3,2,'k'), (3,1,'l'), (1,9,'m');
SELECT a, MAX(b),
(SELECT t.c FROM t1 AS t WHERE t1.a=t.a AND t.b=MAX(t1.b)) AS test
FROM t1 GROUP BY a;
a MAX(b) test
1 9 m
2 3 h
3 4 i
DROP TABLE t1;
mysql-test/r/subselect3.result
View file @ 4410c83f
......@@ -29,7 +29,7 @@ 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 1276 Field or reference 'test.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 `Z` from `test`.`t2`
explain extended
select a, oref from t2
......@@ -38,7 +38,7 @@ id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 5 Using where
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 1276 Field or reference 'test.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
......@@ -91,7 +91,7 @@ id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 4
2 DEPENDENT SUBQUERY t1 index_subquery a a 5 func 2 Using where; Full scan on NULL key
Warnings:
Note 1276 Field or reference 't2.oref' of SELECT #2 was resolved in SELECT #1
Note 1276 Field or reference 'test.t2.oref' of SELECT #2 was resolved in SELECT #1
Note 1003 select `test`.`t2`.`oref` AS `oref`,`test`.`t2`.`a` AS `a`,<in_optimizer>(`test`.`t2`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a checking NULL where (`test`.`t1`.`oref` = `test`.`t2`.`oref`) having trigcond(<is_not_null_test>(`test`.`t1`.`a`))))) AS `Z` from `test`.`t2`
flush status;
select oref, a from t2 where a in (select a from t1 where oref=t2.oref);
......@@ -156,7 +156,7 @@ id select_type table type possible_keys key key_len ref rows Extra
2 DEPENDENT SUBQUERY t1 ref_or_null a a 5 func 4 Using where; Full scan on NULL key
2 DEPENDENT SUBQUERY t2 ref a a 5 test.t1.b 1 Using where
Warnings:
Note 1276 Field or reference 't3.oref' of SELECT #2 was resolved in SELECT #1
Note 1276 Field or reference 'test.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));
......@@ -184,7 +184,7 @@ id select_type table type possible_keys key key_len ref rows Extra
2 DEPENDENT SUBQUERY t1 ref a a 4 func 2 Using where; Full scan on NULL key
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 1276 Field or reference 'test.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);
......@@ -240,7 +240,7 @@ 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 index_subquery a a 5 func 2 Using where; Full scan on NULL key
Warnings:
Note 1276 Field or reference 't2.oref' of SELECT #2 was resolved in SELECT #1
Note 1276 Field or reference 'test.t2.oref' of SELECT #2 was resolved in SELECT #1
Note 1003 select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t2`.`oref` AS `oref`,<in_optimizer>((`test`.`t2`.`a`,`test`.`t2`.`b`),<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on a checking NULL where ((`test`.`t1`.`c` = `test`.`t2`.`oref`) and trigcond(((<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`) or isnull(`test`.`t1`.`a`))) and trigcond(((<cache>(`test`.`t2`.`b`) = `test`.`t1`.`b`) or isnull(`test`.`t1`.`b`)))) having (trigcond(<is_not_null_test>(`test`.`t1`.`a`)) and trigcond(<is_not_null_test>(`test`.`t1`.`b`)))))) AS `Z` from `test`.`t2`
select a,b, oref, (a,b) in (select a,b from t1 where c=t2.oref) Z from t2;
a b oref Z
......@@ -257,7 +257,7 @@ id select_type table type possible_keys key key_len ref rows Extra
2 DEPENDENT SUBQUERY t1 ref_or_null a a 5 func 2 Using where; Full scan on NULL key
2 DEPENDENT SUBQUERY t4 ALL NULL NULL NULL NULL 100 Using where
Warnings:
Note 1276 Field or reference 't2.oref' of SELECT #2 was resolved in SELECT #1
Note 1276 Field or reference 'test.t2.oref' of SELECT #2 was resolved in SELECT #1
Note 1003 select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t2`.`oref` AS `oref`,<in_optimizer>((`test`.`t2`.`a`,`test`.`t2`.`b`),<exists>(select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b` from `test`.`t1` join `test`.`t4` where ((`test`.`t1`.`c` = `test`.`t2`.`oref`) and trigcond(((<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`) or isnull(`test`.`t1`.`a`))) and trigcond(((<cache>(`test`.`t2`.`b`) = `test`.`t1`.`b`) or isnull(`test`.`t1`.`b`)))) having (trigcond(<is_not_null_test>(`test`.`t1`.`a`)) and trigcond(<is_not_null_test>(`test`.`t1`.`b`))))) AS `Z` from `test`.`t2`
select a,b, oref,
(a,b) in (select a,b from t1,t4 where c=t2.oref) Z
......@@ -302,7 +302,7 @@ id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 8 Using where
2 DEPENDENT SUBQUERY t1 index_subquery idx idx 5 func 4 Using where; Full scan on NULL key
Warnings:
Note 1276 Field or reference 't2.oref' of SELECT #2 was resolved in SELECT #1
Note 1276 Field or reference 'test.t2.oref' of SELECT #2 was resolved in SELECT #1
Note 1003 select `test`.`t2`.`oref` AS `oref`,`test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,<in_optimizer>((`test`.`t2`.`a`,`test`.`t2`.`b`),<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on idx checking NULL where ((`test`.`t1`.`oref` = `test`.`t2`.`oref`) and trigcond(((<cache>(`test`.`t2`.`a`) = `test`.`t1`.`ie1`) or isnull(`test`.`t1`.`ie1`))) and trigcond(((<cache>(`test`.`t2`.`b`) = `test`.`t1`.`ie2`) or isnull(`test`.`t1`.`ie2`)))) having (trigcond(<is_not_null_test>(`test`.`t1`.`ie1`)) and trigcond(<is_not_null_test>(`test`.`t1`.`ie2`)))))) AS `Z` from `test`.`t2` where ((`test`.`t2`.`b` = 10) and (`test`.`t2`.`a` = 10))
drop table t1, t2;
create table t1 (oref char(4), grp int, ie int);
......@@ -432,7 +432,7 @@ alter table t1 add index idx(oref,ie);
explain select oref, a, a in (select ie from t1 where oref=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 7
2 DEPENDENT SUBQUERY t1 ref_or_null idx idx 10 test.t2.oref,func 4 Using where; Using index; Full scan on NULL key
2 DEPENDENT SUBQUERY t1 ref_or_null idx idx 10 t2.oref,func 4 Using where; Using index; Full scan on NULL key
select oref, a, a in (select ie from t1 where oref=t2.oref) Z from t2;
oref a Z
ee NULL NULL
......@@ -457,7 +457,7 @@ group by grp having min(ie) > 1) Z
from t2;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 7
2 DEPENDENT SUBQUERY t1 ref idx idx 5 test.t2.oref 2 Using where; Using temporary; Using filesort
2 DEPENDENT SUBQUERY t1 ref idx idx 5 t2.oref 2 Using where; Using temporary; Using filesort
select oref, a,
a in (select min(ie) from t1 where oref=t2.oref
group by grp having min(ie) > 1) Z
......@@ -572,7 +572,7 @@ id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 7
2 DEPENDENT SUBQUERY t1 index_subquery idx idx 5 func 4 Using where; Full scan on NULL key
Warnings:
Note 1276 Field or reference 't2.oref' of SELECT #2 was resolved in SELECT #1
Note 1276 Field or reference 'test.t2.oref' of SELECT #2 was resolved in SELECT #1
Note 1003 select `test`.`t2`.`oref` AS `oref`,`test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,<in_optimizer>((`test`.`t2`.`a`,`test`.`t2`.`b`),<exists>(<index_lookup>(<cache>(`test`.`t2`.`a`) in t1 on idx checking NULL where ((`test`.`t1`.`oref` = `test`.`t2`.`oref`) and trigcond(((<cache>(`test`.`t2`.`a`) = `test`.`t1`.`ie1`) or isnull(`test`.`t1`.`ie1`))) and trigcond(((<cache>(`test`.`t2`.`b`) = `test`.`t1`.`ie2`) or isnull(`test`.`t1`.`ie2`)))) having (trigcond(<is_not_null_test>(`test`.`t1`.`ie1`)) and trigcond(<is_not_null_test>(`test`.`t1`.`ie2`)))))) AS `Z` from `test`.`t2`
drop table t1,t2;
create table t1 (oref char(4), grp int, ie int primary key);
......
mysql-test/t/subselect.test
View file @ 4410c83f
......@@ -2600,4 +2600,31 @@ SELECT * FROM t1
UNION
SELECT c from t2 WHERE c=t1.c);
DROP TABLE t1,t2,t3;
DROP TABLE t1,t2,t3;
#
# Bug#23800: Outer fields in correlated subqueries is used in a temporary
# table created for sorting.
#
CREATE TABLE t1(f1 int);
CREATE TABLE t2(f2 int, f21 int, f3 timestamp);
INSERT INTO t1 VALUES (1),(1),(2),(2);
INSERT INTO t2 VALUES (1,1,"2004-02-29 11:11:11"), (2,2,"2004-02-29 11:11:11");
SELECT ((SELECT f2 FROM t2 WHERE f21=f1 LIMIT 1) * COUNT(f1)) AS sq FROM t1 GROUP BY f1;
SELECT (SELECT SUM(1) FROM t2 ttt GROUP BY t2.f3 LIMIT 1) AS tt FROM t2;
PREPARE stmt1 FROM 'SELECT ((SELECT f2 FROM t2 WHERE f21=f1 LIMIT 1) * COUNT(f1)) AS sq FROM t1 GROUP BY f1';
EXECUTE stmt1;
EXECUTE stmt1;
DEALLOCATE PREPARE stmt1;
SELECT f2, AVG(f21),
(SELECT t.f3 FROM t2 AS t WHERE t2.f2=t.f2 AND t.f3=MAX(t2.f3)) AS test
FROM t2 GROUP BY f2;
DROP TABLE t1,t2;
CREATE TABLE t1 (a int, b INT, c CHAR(10) NOT NULL);
INSERT INTO t1 VALUES
(1,1,'a'), (1,2,'b'), (1,3,'c'), (1,4,'d'), (1,5,'e'),
(2,1,'f'), (2,2,'g'), (2,3,'h'), (3,4,'i'), (3,3,'j'),
(3,2,'k'), (3,1,'l'), (1,9,'m');
SELECT a, MAX(b),
(SELECT t.c FROM t1 AS t WHERE t1.a=t.a AND t.b=MAX(t1.b)) AS test
FROM t1 GROUP BY a;
DROP TABLE t1;
sql/item.cc
View file @ 4410c83f
......@@ -1609,7 +1609,7 @@ void Item_ident_for_show::make_field(Send_field *tmp_field)
Item_field::Item_field(Field *f)
:Item_ident(0, NullS, *f->table_name, f->field_name),
item_equal(0), no_const_subst(0),
have_privileges(0), any_privileges(0)
have_privileges(0), any_privileges(0), fixed_as_field(0)
{
set_field(f);
/*
......@@ -1623,7 +1623,7 @@ Item_field::Item_field(THD *thd, Name_resolution_context *context_arg,
Field *f)
:Item_ident(context_arg, f->table->s->db, *f->table_name, f->field_name),
item_equal(0), no_const_subst(0),
have_privileges(0), any_privileges(0)
have_privileges(0), any_privileges(0), fixed_as_field(0)
{
/*
We always need to provide Item_field with a fully qualified field
......@@ -1662,7 +1662,7 @@ Item_field::Item_field(Name_resolution_context *context_arg,
const char *field_name_arg)
:Item_ident(context_arg, db_arg,table_name_arg,field_name_arg),
field(0), result_field(0), item_equal(0), no_const_subst(0),
have_privileges(0), any_privileges(0)
have_privileges(0), any_privileges(0), fixed_as_field(0)
{
collation.set(DERIVATION_IMPLICIT);
}
......@@ -1675,7 +1675,8 @@ Item_field::Item_field(THD *thd, Item_field *item)
item_equal(item->item_equal),
no_const_subst(item->no_const_subst),
have_privileges(item->have_privileges),
any_privileges(item->any_privileges)
any_privileges(item->any_privileges),
fixed_as_field(item->fixed_as_field)
{
collation.set(DERIVATION_IMPLICIT);
}
......@@ -3484,8 +3485,46 @@ Item_field::fix_outer_field(THD *thd, Field **from_field, Item **reference)
}
if (*from_field != view_ref_found)
{
prev_subselect_item->used_tables_cache|= (*from_field)->table->map;
prev_subselect_item->const_item_cache= 0;
if (!last_checked_context->select_lex->having_fix_field &&
!fixed_as_field)
{
Item_outer_ref *rf;
Query_arena *arena= 0, backup;
/*
Each outer field is replaced for an Item_outer_ref object.
This is done in order to get correct results when the outer
select employs a temporary table.
The original fields are saved in the inner_fields_list of the
outer select. This list is created by the following reasons:
1. We can't add field items to the outer select list directly
because the outer select hasn't been fully fixed yet.
2. We need a location to refer to in the Item_ref object
so the inner_fields_list is used as such temporary
reference storage.
The new Item_outer_ref object replaces the original field and is
also saved in the inner_refs_list of the outer select. Here
it is only created. It can be fixed only after the original
field has been fixed and this is done in the fix_inner_refs()
function.
*/
set_field(*from_field);
arena= thd->activate_stmt_arena_if_needed(&backup);
rf= new Item_outer_ref(context, this);
if (!rf)
{
if (arena)
thd->restore_active_arena(arena, &backup);
return -1;
}
*reference= rf;
select->inner_refs_list.push_back(rf);
if (arena)
thd->restore_active_arena(arena, &backup);
fixed_as_field= 1;
}
if (thd->lex->in_sum_func &&
thd->lex->in_sum_func->nest_level ==
thd->lex->current_select->nest_level)
......@@ -3612,7 +3651,7 @@ Item_field::fix_outer_field(THD *thd, Field **from_field, Item **reference)
{
mark_as_dependent(thd, last_checked_context->select_lex,
context->select_lex,
this, this);
this, (Item_ident*)*reference);
if (last_checked_context->select_lex->having_fix_field)
{
Item_ref *rf;
......@@ -4818,8 +4857,7 @@ Item_ref::Item_ref(Name_resolution_context *context_arg,
/*
This constructor used to create some internals references over fixed items
*/
DBUG_ASSERT(ref != 0);
if (*ref && (*ref)->fixed)
if (ref && *ref && (*ref)->fixed)
set_properties();
}
......@@ -5119,7 +5157,7 @@ void Item_ref::print(String *str)
if (ref)
{
if ((*ref)->type() != Item::CACHE_ITEM && ref_type() != VIEW_REF &&
name && alias_name_used)
ref_type() != OUTER_REF && name && alias_name_used)
{
THD *thd= current_thd;
append_identifier(thd, str, name, (uint) strlen(name));
......@@ -5367,7 +5405,7 @@ bool Item_direct_ref::get_date(TIME *ltime,uint fuzzydate)
/*
Prepare referenced view viewld then call usual Item_direct_ref::fix_fields
Prepare referenced field then call usual Item_direct_ref::fix_fields
SYNOPSIS
Item_direct_view_ref::fix_fields()
......@@ -5390,6 +5428,30 @@ bool Item_direct_view_ref::fix_fields(THD *thd, Item **reference)
return Item_direct_ref::fix_fields(thd, reference);
}
/*
Prepare referenced outer field then call usual Item_direct_ref::fix_fields
SYNOPSIS
Item_outer_ref::fix_fields()
thd thread handler
reference reference on reference where this item stored
RETURN
FALSE OK
TRUE Error
*/
bool Item_outer_ref::fix_fields(THD *thd, Item **reference)
{
DBUG_ASSERT(*ref);
/* outer_field->check_cols() will be made in Item_direct_ref::fix_fields */
outer_field->fixed_as_field= 1;
if (!outer_field->fixed &&
(outer_field->fix_fields(thd, reference)))
return TRUE;
return Item_direct_ref::fix_fields(thd, reference);
}
/*
Compare two view column references for equality.
......
sql/item.h
View file @ 4410c83f
......@@ -1214,7 +1214,7 @@ class Item_field :public Item_ident
uint have_privileges;
/* field need any privileges (for VIEW creation) */
bool any_privileges;
bool fixed_as_field;
Item_field(Name_resolution_context *context_arg,
const char *db_arg,const char *table_name_arg,
const char *field_name_arg);
......@@ -1817,7 +1817,7 @@ class Item_ref :public Item_ident
protected:
void set_properties();
public:
enum Ref_Type { REF, DIRECT_REF, VIEW_REF };
enum Ref_Type { REF, DIRECT_REF, VIEW_REF, OUTER_REF };
Field *result_field; /* Save result here */
Item **ref;
Item_ref(Name_resolution_context *context_arg,
......@@ -1878,7 +1878,7 @@ class Item_ref :public Item_ident
(*ref)->get_tmp_table_item(thd));
}
table_map used_tables() const
{
{
return depended_from ? OUTER_REF_TABLE_BIT : (*ref)->used_tables();
}
table_map not_null_tables() const { return (*ref)->not_null_tables(); }
......@@ -1951,6 +1951,40 @@ class Item_direct_view_ref :public Item_direct_ref
};
class Item_outer_ref :public Item_direct_ref
{
public:
Item_field *outer_field;
Item_outer_ref(Name_resolution_context *context_arg,
Item_field *outer_field_arg)
:Item_direct_ref(context_arg, 0, outer_field_arg->table_name,
outer_field_arg->field_name),
outer_field(outer_field_arg)
{
ref= (Item**)&outer_field;
set_properties();
fixed= 0;
}
void cleanup()
{
ref= (Item**)&outer_field;
fixed= 0;
Item_direct_ref::cleanup();
outer_field->cleanup();
}
void save_in_result_field(bool no_conversions)
{
outer_field->save_org_in_field(result_field);
}
bool fix_fields(THD *, Item **);
table_map used_tables() const
{
return (*ref)->const_item() ? 0 : OUTER_REF_TABLE_BIT;
}
virtual Ref_Type ref_type() { return OUTER_REF; }
};
class Item_in_subselect;
......
sql/mysql_priv.h
View file @ 4410c83f
......@@ -747,6 +747,8 @@ int setup_order(THD *thd, Item **ref_pointer_array, TABLE_LIST *tables,
int setup_group(THD *thd, Item **ref_pointer_array, TABLE_LIST *tables,
List<Item> &fields, List<Item> &all_fields, ORDER *order,
bool *hidden_group_fields);
bool fix_inner_refs(THD *thd, List<Item> &all_fields, SELECT_LEX *select,
Item **ref_pointer_array);
bool handle_select(THD *thd, LEX *lex, select_result *result,
ulong setup_tables_done_option);
......
sql/sql_delete.cc
View file @ 4410c83f
......@@ -353,6 +353,7 @@ bool mysql_prepare_delete(THD *thd, TABLE_LIST *table_list, Item **conds)
Item *fake_conds= 0;
SELECT_LEX *select_lex= &thd->lex->select_lex;
DBUG_ENTER("mysql_prepare_delete");
List<Item> all_fields;
thd->lex->allow_sum_func= 0;
if (setup_tables_and_check_access(thd, &thd->lex->select_lex.context,
......@@ -376,6 +377,11 @@ bool mysql_prepare_delete(THD *thd, TABLE_LIST *table_list, Item **conds)
DBUG_RETURN(TRUE);
}
}
if (select_lex->inner_refs_list.elements &&
fix_inner_refs(thd, all_fields, select_lex, select_lex->ref_pointer_array))
DBUG_RETURN(-1);
select_lex->fix_prepare_information(thd, conds, &fake_conds);
DBUG_RETURN(FALSE);
}
......
sql/sql_lex.cc
View file @ 4410c83f
......@@ -1192,6 +1192,7 @@ void st_select_lex::init_select()
is_correlated= 0;
cur_pos_in_select_list= UNDEF_POS;
non_agg_fields.empty();
inner_refs_list.empty();
}
/*
......
sql/sql_lex.h
View file @ 4410c83f
......@@ -547,7 +547,8 @@ class st_select_lex: public st_select_lex_node
bool braces; /* SELECT ... UNION (SELECT ... ) <- this braces */
/* TRUE when having fix field called in processing of this SELECT */
bool having_fix_field;
/* List of references to fields referenced from inner selects */
List<Item_outer_ref> inner_refs_list;
/* Number of Item_sum-derived objects in this SELECT */
uint n_sum_items;
/* Number of Item_sum-derived objects in children and descendant SELECTs */
......
sql/sql_select.cc
View file @ 4410c83f
......@@ -268,6 +268,70 @@ bool handle_select(THD *thd, LEX *lex, select_result *result,
}
/*
Fix fields referenced from inner selects.
SYNOPSIS
fix_inner_refs()
thd Thread handle
all_fields List of all fields used in select
select Current select
ref_pointer_array Array of references to Items used in current select
DESCRIPTION
The function fixes fields referenced from inner selects and
also fixes references (Item_ref objects) to these fields. Each field
is fixed as a usual hidden field of the current select - it is added
to the all_fields list and the pointer to it is saved in the
ref_pointer_array if latter is provided.
After the field has been fixed we proceed with fixing references
(Item_ref objects) to this field from inner subqueries. If the
ref_pointer_array is provided then Item_ref objects is set to
reference element in that array with the pointer to the field.
RETURN
TRUE an error occured
FALSE ok
*/
bool
fix_inner_refs(THD *thd, List<Item> &all_fields, SELECT_LEX *select,
Item **ref_pointer_array)
{
Item_outer_ref *ref;
bool res= FALSE;
List_iterator<Item_outer_ref> ref_it(select->inner_refs_list);
while ((ref= ref_it++))
{
Item_field *item= ref->outer_field;
/*
TODO: this field item already might be present in the select list.
In this case instead of adding new field item we could use an
existing one. The change will lead to less operations for copying fields,
smaller temporary tables and less data passed through filesort.
*/
if (ref_pointer_array)
{
int el= all_fields.elements;
ref_pointer_array[el]= (Item*)item;
/* Add the field item to the select list of the current select. */
all_fields.push_front((Item*)item);
/*
If it's needed reset each Item_ref item that refers this field with
a new reference taken from ref_pointer_array.
*/
ref->ref= ref_pointer_array + el;
}
if (!ref->fixed && ref->fix_fields(thd, 0))
{
res= TRUE;
break;
}
thd->used_tables|= item->used_tables();
}
return res;
}
/*
Function to setup clauses without sum functions
*/
......@@ -395,6 +459,10 @@ JOIN::prepare(Item ***rref_pointer_array,
if (having && having->with_sum_func)
having->split_sum_func2(thd, ref_pointer_array, all_fields,
&having, TRUE);
if (select_lex->inner_refs_list.elements &&
fix_inner_refs(thd, all_fields, select_lex, ref_pointer_array))
DBUG_RETURN(-1);
if (select_lex->inner_sum_func_list)
{
Item_sum *end=select_lex->inner_sum_func_list;
......@@ -5133,13 +5201,15 @@ get_store_key(THD *thd, KEYUSE *keyuse, table_map used_tables,
key_part->length,
keyuse->val);
}
else if (keyuse->val->type() == Item::FIELD_ITEM)
else if (keyuse->val->type() == Item::FIELD_ITEM ||
(keyuse->val->type() == Item::REF_ITEM &&
((Item_ref*)keyuse->val)->ref_type() == Item_ref::OUTER_REF) )
return new store_key_field(thd,
key_part->field,
key_buff + maybe_null,
maybe_null ? key_buff : 0,
key_part->length,
((Item_field*) keyuse->val)->field,
((Item_field*) keyuse->val->real_item())->field,
keyuse->val->full_name());
return new store_key_item(thd,
key_part->field,
......@@ -8697,7 +8767,8 @@ static Field *create_tmp_field_from_item(THD *thd, Item *item, TABLE *table,
type they needed to be handled separately.
*/
if ((type= item->field_type()) == MYSQL_TYPE_DATETIME ||
type == MYSQL_TYPE_TIME || type == MYSQL_TYPE_DATE)
type == MYSQL_TYPE_TIME || type == MYSQL_TYPE_DATE ||
type == MYSQL_TYPE_TIMESTAMP)
new_field= item->tmp_table_field_from_field_type(table);
/*
Make sure that the blob fits into a Field_varstring which has
......@@ -8804,8 +8875,7 @@ Field *create_tmp_field(THD *thd, TABLE *table,Item *item, Item::Type type,
Item *orig_item= 0;
if (type != Item::FIELD_ITEM &&
item->real_item()->type() == Item::FIELD_ITEM &&
!((Item_ref *) item)->depended_from)
item->real_item()->type() == Item::FIELD_ITEM)
{
orig_item= item;
item= item->real_item();
......@@ -13465,8 +13535,7 @@ count_field_types(TMP_TABLE_PARAM *param, List<Item> &fields,
{
Item::Type type=field->type();
Item::Type real_type= field->real_item()->type();
if (type == Item::FIELD_ITEM || (real_type == Item::FIELD_ITEM &&
!((Item_ref *) field)->depended_from))
if (real_type == Item::FIELD_ITEM)
param->field_count++;
else if (real_type == Item::SUM_FUNC_ITEM)
{
......
sql/sql_update.cc
View file @ 4410c83f
......@@ -134,6 +134,7 @@ int mysql_update(THD *thd,
READ_RECORD info;
SELECT_LEX *select_lex= &thd->lex->select_lex;
bool need_reopen;
List<Item> all_fields;
DBUG_ENTER("mysql_update");
LINT_INIT(timestamp_query_id);
......@@ -226,6 +227,10 @@ int mysql_update(THD *thd,
DBUG_RETURN(1); /* purecov: inspected */
}
if (select_lex->inner_refs_list.elements &&
fix_inner_refs(thd, all_fields, select_lex, select_lex->ref_pointer_array))
DBUG_RETURN(-1);
if (conds)
{
Item::cond_result cond_value;
......
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