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mariadb/mysql-test/r/derived.result
Sergey Glukhov fcb83cbf15 Fixed following problems: 
--Bug#52157 various crashes and assertions with multi-table update, stored function
--Bug#54475 improper error handling causes cascading crashing failures in innodb/ndb
--Bug#57703 create view cause Assertion failed: 0, file .\item_subselect.cc, line 846
--Bug#57352 valgrind warnings when creating view
--Recently discovered problem when a nested materialized derived table is used
  before being populated and it leads to incorrect result

We have several modes when we should disable subquery evaluation.
The reasons for disabling are different. It could be
uselessness of the evaluation as in case of 'CREATE VIEW'
or 'PREPARE stmt', or we should disable subquery evaluation
if tables are not locked yet as it happens in bug#54475, or
too early evaluation of subqueries can lead to wrong result
as it happened in Bug#19077.
Main problem is that if subquery items are treated as const
they are evaluated in ::fix_fields(), ::fix_length_and_dec()
of the parental items as a lot of these methods have
Item::val_...() calls inside.
We have to make subqueries non-const to prevent unnecessary
subquery evaluation. At the moment we have different methods
for this. Here is a list of these modes:

1. PREPARE stmt;
We use UNCACHEABLE_PREPARE flag.
It is set during parsing in sql_parse.cc, mysql_new_select() for
each SELECT_LEX object and cleared at the end of PREPARE in
sql_prepare.cc, init_stmt_after_parse(). If this flag is set
subquery becomes non-const and evaluation does not happen.

2. CREATE|ALTER VIEW, SHOW CREATE VIEW, I_S tables which
   process FRM files
We use LEX::view_prepare_mode field. We set it before
view preparation and check this flag in
::fix_fields(), ::fix_length_and_dec().
Some bugs are fixed using this approach,
some are not(Bug#57352, Bug#57703). The problem here is
that we have a lot of ::fix_fields(), ::fix_length_and_dec()
where we use Item::val_...() calls for const items.

3. Derived tables with subquery = wrong result(Bug19077)
The reason of this bug is too early subquery evaluation.
It was fixed by adding Item::with_subselect field
The check of this field in appropriate places prevents
const item evaluation if the item have subquery.
The fix for Bug19077 fixes only the problem with
convert_constant_item() function and does not cover
other places(::fix_fields(), ::fix_length_and_dec() again)
where subqueries could be evaluated.

Example:
CREATE TABLE t1 (i INT, j BIGINT);
INSERT INTO t1 VALUES (1, 2), (2, 2), (3, 2);
SELECT * FROM (SELECT MIN(i) FROM t1
WHERE j = SUBSTRING('12', (SELECT * FROM (SELECT MIN(j) FROM t1) t2))) t3;
DROP TABLE t1;

4. Derived tables with subquery where subquery
   is evaluated before table locking(Bug#54475, Bug#52157)

Suggested solution is following:

-Introduce new field LEX::context_analysis_only with the following
 possible flags:
 #define CONTEXT_ANALYSIS_ONLY_PREPARE 1
 #define CONTEXT_ANALYSIS_ONLY_VIEW    2
 #define CONTEXT_ANALYSIS_ONLY_DERIVED 4
-Set/clean these flags when we perform
 context analysis operation
-Item_subselect::const_item() returns
 result depending on LEX::context_analysis_only.
 If context_analysis_only is set then we return
 FALSE that means that subquery is non-const.
 As all subquery types are wrapped by Item_subselect
 it allow as to make subquery non-const when
 it's necessary.


mysql-test/r/derived.result:
  test case
mysql-test/r/multi_update.result:
  test case
mysql-test/r/view.result:
  test case
mysql-test/suite/innodb/r/innodb_multi_update.result:
  test case
mysql-test/suite/innodb/t/innodb_multi_update.test:
  test case
mysql-test/suite/innodb_plugin/r/innodb_multi_update.result:
  test case
mysql-test/suite/innodb_plugin/t/innodb_multi_update.test:
  test case
mysql-test/t/derived.test:
  test case
mysql-test/t/multi_update.test:
  test case
mysql-test/t/view.test:
  test case
sql/item.cc:
  --removed unnecessary code
sql/item_cmpfunc.cc:
  --removed unnecessary checks
  --THD::is_context_analysis_only() is replaced with LEX::is_ps_or_view_context_analysis()
sql/item_func.cc:
  --refactored context analysis checks
sql/item_row.cc:
  --removed unnecessary checks
sql/item_subselect.cc:
  --removed unnecessary code
  --added DBUG_ASSERT into Item_subselect::exec()
    which asserts that subquery execution can not happen
    if LEX::context_analysis_only is set, i.e. at context
    analysis stage.
  --Item_subselect::const_item()
    Return FALSE if LEX::context_analysis_only is set.
    It prevents subquery evaluation in ::fix_fields &
    ::fix_length_and_dec at context analysis stage.
sql/item_subselect.h:
  --removed unnecessary code
sql/mysql_priv.h:
  --Added new set of flags.
sql/sql_class.h:
  --removed unnecessary code
sql/sql_derived.cc:
  --added LEX::context_analysis_only analysis intialization/cleanup
sql/sql_lex.cc:
  --init LEX::context_analysis_only field
sql/sql_lex.h:
  --New LEX::context_analysis_only field
sql/sql_parse.cc:
  --removed unnecessary code
sql/sql_prepare.cc:
  --removed unnecessary code
  --added LEX::context_analysis_only analysis intialization/cleanup
sql/sql_select.cc:
  --refactored context analysis checks
sql/sql_show.cc:
  --added LEX::context_analysis_only analysis intialization/cleanup
sql/sql_view.cc:
  --added LEX::context_analysis_only analysis intialization/cleanup
2010-12-14 12:33:03 +03:00

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drop table if exists t1,t2,t3;
select * from (select 2 from DUAL) b;
2
2
SELECT 1 as a FROM (SELECT 1 UNION SELECT a) b;
ERROR 42S22: Unknown column 'a' in 'field list'
SELECT 1 as a FROM (SELECT a UNION SELECT 1) b;
ERROR 42S22: Unknown column 'a' in 'field list'
CREATE TABLE t1 (a int not null, b char (10) not null);
insert into t1 values(1,'a'),(2,'b'),(3,'c'),(3,'c');
CREATE TABLE t2 (a int not null, b char (10) not null);
insert into t2 values (3,'c'),(4,'d'),(5,'f'),(6,'e');
select t1.a,t3.y from t1,(select a as y from t2 where b='c') as t3 where t1.a = t3.y;
a y
3 3
3 3
select t1.a,t3.a from t1,(select * from t2 where b='c') as t3 where t1.a = t3.a;
a a
3 3
3 3
CREATE TABLE t3 (a int not null, b char (10) not null);
insert into t3 values (3,'f'),(4,'y'),(5,'z'),(6,'c');
select t1.a,t4.y from t1,(select t2.a as y from t2,(select t3.b from t3 where t3.a>3) as t5 where t2.b=t5.b) as t4 where t1.a = t4.y;
a y
3 3
3 3
SELECT a FROM (SELECT 1 FROM (SELECT 1) a HAVING a=1) b;
ERROR 42S22: Unknown column 'a' in 'having clause'
SELECT a,b as a FROM (SELECT '1' as a,'2' as b) b HAVING a=1;
ERROR 23000: Column 'a' in having clause is ambiguous
SELECT a,2 as a FROM (SELECT '1' as a) b HAVING a=2;
a a
1 2
SELECT a,2 as a FROM (SELECT '1' as a) b HAVING a=1;
a a
SELECT 1 FROM (SELECT 1) a WHERE a=2;
ERROR 42S22: Unknown column 'a' in 'where clause'
SELECT (SELECT 1) as a FROM (SELECT 1 FROM t1 HAVING a=1) as a;
ERROR 42S22: Unknown column 'a' in 'having clause'
select * from t1 as x1, (select * from t1) as x2;
a b a b
1 a 1 a
2 b 1 a
3 c 1 a
3 c 1 a
1 a 2 b
2 b 2 b
3 c 2 b
3 c 2 b
1 a 3 c
2 b 3 c
3 c 3 c
3 c 3 c
1 a 3 c
2 b 3 c
3 c 3 c
3 c 3 c
explain select * from t1 as x1, (select * from t1) as x2;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY x1 ALL NULL NULL NULL NULL 4
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 4 Using join buffer
2 DERIVED t1 ALL NULL NULL NULL NULL 4
drop table if exists t2,t3;
select * from (select 1) as a;
1
1
select a from (select 1 as a) as b;
a
1
select 1 from (select 1) as a;
1
1
select * from (select * from t1 union select * from t1) a;
a b
1 a
2 b
3 c
select * from (select * from t1 union all select * from t1) a;
a b
1 a
2 b
3 c
3 c
1 a
2 b
3 c
3 c
select * from (select * from t1 union all select * from t1 limit 2) a;
a b
1 a
2 b
explain select * from (select * from t1 union select * from t1) a;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 3
2 DERIVED t1 ALL NULL NULL NULL NULL 4
3 UNION t1 ALL NULL NULL NULL NULL 4
NULL UNION RESULT <union2,3> ALL NULL NULL NULL NULL NULL
explain select * from (select * from t1 union all select * from t1) a;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 8
2 DERIVED t1 ALL NULL NULL NULL NULL 4
3 UNION t1 ALL NULL NULL NULL NULL 4
NULL UNION RESULT <union2,3> ALL NULL NULL NULL NULL NULL
CREATE TABLE t2 (a int not null);
insert into t2 values(1);
select * from (select * from t1 where t1.a=(select a from t2 where t2.a=t1.a)) a;
a b
1 a
select * from (select * from t1 where t1.a=(select t2.a from t2 where t2.a=t1.a) union select t1.a, t1.b from t1) a;
a b
1 a
2 b
3 c
explain select * from (select t1.*, t2.a as t2a from t1,t2 where t1.a=t2.a) t1;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> system NULL NULL NULL NULL 1
2 DERIVED t2 system NULL NULL NULL NULL 1
2 DERIVED t1 ALL NULL NULL NULL NULL 4 Using where
drop table t1, t2;
create table t1(a int not null, t char(8), index(a));
SELECT * FROM (SELECT * FROM t1) as b ORDER BY a ASC LIMIT 0,20;
a t
1 1
2 2
3 3
4 4
5 5
6 6
7 7
8 8
9 9
10 10
11 11
12 12
13 13
14 14
15 15
16 16
17 17
18 18
19 19
20 20
explain select count(*) from t1 as tt1, (select * from t1) as tt2;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
2 DERIVED t1 ALL NULL NULL NULL NULL 10000
drop table t1;
SELECT * FROM (SELECT (SELECT * FROM (SELECT 1 as a) as a )) as b;
(SELECT * FROM (SELECT 1 as a) as a )
1
select * from (select 1 as a) b left join (select 2 as a) c using(a);
a
1
SELECT * FROM (SELECT 1 UNION SELECT a) b;
ERROR 42S22: Unknown column 'a' in 'field list'
SELECT 1 as a FROM (SELECT a UNION SELECT 1) b;
ERROR 42S22: Unknown column 'a' in 'field list'
SELECT 1 as a FROM (SELECT 1 UNION SELECT a) b;
ERROR 42S22: Unknown column 'a' in 'field list'
select 1 from (select 2) a order by 0;
ERROR 42S22: Unknown column '0' in 'order clause'
create table t1 (id int);
insert into t1 values (1),(2),(3);
describe select * from (select * from t1 group by id) bar;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 3
2 DERIVED t1 ALL NULL NULL NULL NULL 3 Using temporary; Using filesort
drop table t1;
create table t1 (mat_id MEDIUMINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY, matintnum CHAR(6) NOT NULL, test MEDIUMINT UNSIGNED NULL);
create table t2 (mat_id MEDIUMINT UNSIGNED NOT NULL, pla_id MEDIUMINT UNSIGNED NOT NULL);
insert into t1 values (NULL, 'a', 1), (NULL, 'b', 2), (NULL, 'c', 3), (NULL, 'd', 4), (NULL, 'e', 5), (NULL, 'f', 6), (NULL, 'g', 7), (NULL, 'h', 8), (NULL, 'i', 9);
insert into t2 values (1, 100), (1, 101), (1, 102), (2, 100), (2, 103), (2, 104), (3, 101), (3, 102), (3, 105);
SELECT STRAIGHT_JOIN d.pla_id, m2.mat_id FROM t1 m2 INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum;
pla_id mat_id
100 1
101 1
102 1
103 2
104 2
105 3
SELECT STRAIGHT_JOIN d.pla_id, m2.test FROM t1 m2 INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum;
pla_id test
100 1
101 1
102 1
103 2
104 2
105 3
explain SELECT STRAIGHT_JOIN d.pla_id, m2.mat_id FROM t1 m2 INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY m2 ALL NULL NULL NULL NULL 9
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 6 Using where; Using join buffer
2 DERIVED mp ALL NULL NULL NULL NULL 9 Using temporary; Using filesort
2 DERIVED m1 eq_ref PRIMARY PRIMARY 3 test.mp.mat_id 1
explain SELECT STRAIGHT_JOIN d.pla_id, m2.test FROM t1 m2 INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY m2 ALL NULL NULL NULL NULL 9
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 6 Using where; Using join buffer
2 DERIVED mp ALL NULL NULL NULL NULL 9 Using temporary; Using filesort
2 DERIVED m1 eq_ref PRIMARY PRIMARY 3 test.mp.mat_id 1
drop table t1,t2;
SELECT a.x FROM (SELECT 1 AS x) AS a HAVING a.x = 1;
x
1
create user mysqltest_1;
create table t1 select 1 as a;
select 2 as a from (select * from t1) b;
ERROR 3D000: No database selected
use test;
select 2 as a from (select * from t1) b;
a
2
drop table t1;
select mail_id, if(folder.f_description!='', folder.f_description, folder.f_name) as folder_name, date, address_id, phrase, address, subject from folder, (select mail.mail_id as mail_id, date_format(mail.h_date, '%b %e, %Y %h:%i') as date, mail.folder_id, sender.address_id as address_id, sender.phrase as phrase, sender.address as address, mail.h_subject as subject from mail left join mxa as mxa_sender on mail.mail_id=mxa_sender.mail_id and mxa_sender.type='from' left join address as sender on mxa_sender.address_id=sender.address_id mxa as mxa_recipient, address as recipient, where 1 and mail.mail_id=mxa_recipient.mail_id and mxa_recipient.address_id=recipient.address_id and mxa_recipient.type='to' and match(sender.phrase, sender.address, sender.comment) against ('jeremy' in boolean mode) and match(recipient.phrase, recipient.address, recipient.comment) against ('monty' in boolean mode) order by mail.h_date desc limit 0, 25 ) as query where query.folder_id=folder.folder_id;
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'mxa as mxa_recipient, address as recipient, where 1 and mail.mail_id=mxa_r' at line 1
create table t1 (a int);
insert into t1 values (1),(2),(3);
update (select * from t1) as t1 set a = 5;
ERROR HY000: The target table t1 of the UPDATE is not updatable
delete from (select * from t1);
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '(select * from t1)' at line 1
insert into (select * from t1) values (5);
ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '(select * from t1) values (5)' at line 1
drop table t1;
create table t1 (E1 INTEGER UNSIGNED NOT NULL, E2 INTEGER UNSIGNED NOT NULL, E3 INTEGER UNSIGNED NOT NULL, PRIMARY KEY(E1)
);
insert into t1 VALUES(1,1,1), (2,2,1);
select count(*) from t1 INNER JOIN (SELECT A.E1, A.E2, A.E3 FROM t1 AS A WHERE A.E3 = (SELECT MAX(B.E3) FROM t1 AS B WHERE A.E2 = B.E2)) AS THEMAX ON t1.E1 = THEMAX.E2 AND t1.E1 = t1.E2;
count(*)
2
explain select count(*) from t1 INNER JOIN (SELECT A.E1, A.E2, A.E3 FROM t1 AS A WHERE A.E3 = (SELECT MAX(B.E3) FROM t1 AS B WHERE A.E2 = B.E2)) AS THEMAX ON t1.E1 = THEMAX.E2 AND t1.E1 = t1.E2;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2
1 PRIMARY t1 eq_ref PRIMARY PRIMARY 4 THEMAX.E2 1 Using where
2 DERIVED A ALL NULL NULL NULL NULL 2 Using where
3 DEPENDENT SUBQUERY B ALL NULL NULL NULL NULL 2 Using where
drop table t1;
create table t1 (a int);
insert into t1 values (1),(2);
select * from ( select * from t1 union select * from t1) a,(select * from t1 union select * from t1) b;
a a
1 1
2 1
1 2
2 2
explain select * from ( select * from t1 union select * from t1) a,(select * from t1 union select * from t1) b;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 2
1 PRIMARY <derived4> ALL NULL NULL NULL NULL 2 Using join buffer
4 DERIVED t1 ALL NULL NULL NULL NULL 2
5 UNION t1 ALL NULL NULL NULL NULL 2
NULL UNION RESULT <union4,5> ALL NULL NULL NULL NULL NULL
2 DERIVED t1 ALL NULL NULL NULL NULL 2
3 UNION t1 ALL NULL NULL NULL NULL 2
NULL UNION RESULT <union2,3> ALL NULL NULL NULL NULL NULL
drop table t1;
CREATE TABLE `t1` (
`N` int(11) unsigned NOT NULL default '0',
`M` tinyint(1) default '0'
) ENGINE=MyISAM DEFAULT CHARSET=latin1;
INSERT INTO `t1` (N, M) VALUES (1, 0),(1, 0),(1, 0),(2, 0),(2, 0),(3, 0);
UPDATE `t1` AS P1 INNER JOIN (SELECT N FROM `t1` GROUP BY N HAVING Count(M) > 1) AS P2 ON P1.N = P2.N SET P1.M = 2;
select * from t1;
N M
1 2
1 2
1 2
2 2
2 2
3 0
UPDATE `t1` AS P1 INNER JOIN (SELECT N FROM `t1` GROUP BY N HAVING Count(M) > 1) AS P2 ON P1.N = P2.N SET P1.M = 2, P2.N = 2;
ERROR HY000: The target table P2 of the UPDATE is not updatable
UPDATE `t1` AS P1 INNER JOIN (SELECT aaaa FROM `t1` GROUP BY N HAVING Count(M) > 1) AS P2 ON P1.N = P2.N SET P1.M = 2;
ERROR 42S22: Unknown column 'aaaa' in 'field list'
delete P1.* from `t1` AS P1 INNER JOIN (SELECT N FROM `t1` GROUP BY N HAVING Count(M) > 1) AS P2 ON P1.N = P2.N;
select * from t1;
N M
3 0
delete P1.*,p2.* from `t1` AS P1 INNER JOIN (SELECT N FROM `t1` GROUP BY N HAVING Count(M) > 1) AS p2 ON P1.N = p2.N;
ERROR 42S02: Unknown table 'p2' in MULTI DELETE
delete P1.* from `t1` AS P1 INNER JOIN (SELECT aaa FROM `t1` GROUP BY N HAVING Count(M) > 1) AS P2 ON P1.N = P2.N;
ERROR 42S22: Unknown column 'aaa' in 'field list'
drop table t1;
CREATE TABLE t1 (
OBJECTID int(11) NOT NULL default '0',
SORTORDER int(11) NOT NULL auto_increment,
KEY t1_SortIndex (SORTORDER),
KEY t1_IdIndex (OBJECTID)
) ENGINE=MyISAM DEFAULT CHARSET=latin1;
CREATE TABLE t2 (
ID int(11) default NULL,
PARID int(11) default NULL,
UNIQUE KEY t2_ID_IDX (ID),
KEY t2_PARID_IDX (PARID)
) engine=MyISAM DEFAULT CHARSET=latin1;
INSERT INTO t2 VALUES (1000,0),(1001,0),(1002,0),(1003,0),(1008,1),(1009,1),(1010,1),(1011,1),(1016,2);
CREATE TABLE t3 (
ID int(11) default NULL,
DATA decimal(10,2) default NULL,
UNIQUE KEY t3_ID_IDX (ID)
) engine=MyISAM DEFAULT CHARSET=latin1;
INSERT INTO t3 VALUES (1000,0.00),(1001,0.25),(1002,0.50),(1003,0.75),(1008,1.00),(1009,1.25),(1010,1.50),(1011,1.75);
select 497, TMP.ID, NULL from (select 497 as ID, MAX(t3.DATA) as DATA from t1 join t2 on (t1.ObjectID = t2.ID) join t3 on (t1.ObjectID = t3.ID) group by t2.ParID order by DATA DESC) as TMP;
497 ID NULL
drop table t1, t2, t3;
CREATE TABLE t1 (name char(1) default NULL, val int(5) default NULL);
INSERT INTO t1 VALUES ('a',1), ('a',2), ('a',2), ('a',2), ('a',3), ('a',6), ('a',7), ('a',11), ('a',11), ('a',12), ('a',13), ('a',13), ('a',20), ('b',2), ('b',3), ('b',4), ('b',5);
SELECT s.name, AVG(s.val) AS median FROM (SELECT x.name, x.val FROM t1 x, t1 y WHERE x.name=y.name GROUP BY x.name, x.val HAVING SUM(y.val <= x.val) >= COUNT(*)/2 AND SUM(y.val >= x.val) >= COUNT(*)/2) AS s GROUP BY s.name;
name median
a 7.0000
b 3.5000
explain SELECT s.name, AVG(s.val) AS median FROM (SELECT x.name, x.val FROM t1 x, t1 y WHERE x.name=y.name GROUP BY x.name, x.val HAVING SUM(y.val <= x.val) >= COUNT(*)/2 AND SUM(y.val >= x.val) >= COUNT(*)/2) AS s GROUP BY s.name;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 3 Using temporary; Using filesort
2 DERIVED x ALL NULL NULL NULL NULL 17 Using temporary; Using filesort
2 DERIVED y ALL NULL NULL NULL NULL 17 Using where; Using join buffer
drop table t1;
create table t2 (a int, b int, primary key (a));
insert into t2 values (1,7),(2,7);
explain select a from t2 where a>1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 index PRIMARY PRIMARY 4 NULL 2 Using where; Using index
explain select a from (select a from t2 where a>1) tt;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> system NULL NULL NULL NULL 1
2 DERIVED t2 index PRIMARY PRIMARY 4 NULL 2 Using where; Using index
drop table t2;
CREATE TABLE `t1` ( `itemid` int(11) NOT NULL default '0', `grpid` varchar(15) NOT NULL default '', `vendor` int(11) NOT NULL default '0', `date_` date NOT NULL default '0000-00-00', `price` decimal(12,2) NOT NULL default '0.00', PRIMARY KEY (`itemid`,`grpid`,`vendor`,`date_`), KEY `itemid` (`itemid`,`vendor`), KEY `itemid_2` (`itemid`,`date_`));
insert into t1 values (128, 'rozn', 2, curdate(), 10),
(128, 'rozn', 1, curdate(), 10);
SELECT MIN(price) min, MAX(price) max, AVG(price) avg FROM (SELECT SUBSTRING( MAX(concat(date_,";",price)), 12) price FROM t1 WHERE itemid=128 AND grpid='rozn' GROUP BY itemid, grpid, vendor) lastprices;
min max avg
10.00 10.00 10
DROP TABLE t1;
create table t1 (a integer, b integer);
insert into t1 values (1,4), (2,2),(2,2), (4,1),(4,1),(4,1),(4,1);
select distinct sum(b) from t1 group by a;
sum(b)
4
select distinct sum(b) from (select a,b from t1) y group by a;
sum(b)
4
drop table t1;
CREATE TABLE t1 (a char(10), b char(10));
INSERT INTO t1 VALUES ('root','localhost'), ('root','%');
SELECT * FROM (SELECT (SELECT a.a FROM t1 AS a WHERE a.a = b.a) FROM t1 AS b) AS c;
ERROR 21000: Subquery returns more than 1 row
DROP TABLE t1;
create table t1(a int);
create table t2(a int);
create table t3(a int);
insert into t1 values(1),(1);
insert into t2 values(2),(2);
insert into t3 values(3),(3);
select * from t1 union distinct select * from t2 union all select * from t3;
a
1
2
3
3
select * from (select * from t1 union distinct select * from t2 union all select * from t3) X;
a
1
2
3
3
drop table t1, t2, t3;
create table t1 (a int);
create table t2 (a int);
select * from (select * from t1,t2) foo;
ERROR 42S21: Duplicate column name 'a'
drop table t1,t2;
create table t1 (ID int unsigned not null auto_increment,
DATA varchar(5) not null, primary key (ID));
create table t2 (ID int unsigned not null auto_increment,
DATA varchar(5) not null, FID int unsigned not null,
primary key (ID));
select A.* from (t1 inner join (select * from t2) as A on t1.ID = A.FID);
ID DATA FID
select t2.* from ((select * from t1) as A inner join t2 on A.ID = t2.FID);
ID DATA FID
select t2.* from (select * from t1) as A inner join t2 on A.ID = t2.FID;
ID DATA FID
drop table t1, t2;
drop user mysqltest_1;
# End of 4.1 tests
SELECT 0 FROM
(SELECT 0) t01, (SELECT 0) t02, (SELECT 0) t03, (SELECT 0) t04, (SELECT 0) t05,
(SELECT 0) t06, (SELECT 0) t07, (SELECT 0) t08, (SELECT 0) t09, (SELECT 0) t10,
(SELECT 0) t11, (SELECT 0) t12, (SELECT 0) t13, (SELECT 0) t14, (SELECT 0) t15,
(SELECT 0) t16, (SELECT 0) t17, (SELECT 0) t18, (SELECT 0) t19, (SELECT 0) t20,
(SELECT 0) t21, (SELECT 0) t22, (SELECT 0) t23, (SELECT 0) t24, (SELECT 0) t25,
(SELECT 0) t26, (SELECT 0) t27, (SELECT 0) t28, (SELECT 0) t29, (SELECT 0) t30,
(SELECT 0) t31, (SELECT 0) t32, (SELECT 0) t33, (SELECT 0) t34, (SELECT 0) t35,
(SELECT 0) t36, (SELECT 0) t37, (SELECT 0) t38, (SELECT 0) t39, (SELECT 0) t40,
(SELECT 0) t41, (SELECT 0) t42, (SELECT 0) t43, (SELECT 0) t44, (SELECT 0) t45,
(SELECT 0) t46, (SELECT 0) t47, (SELECT 0) t48, (SELECT 0) t49, (SELECT 0) t50,
(SELECT 0) t51, (SELECT 0) t52, (SELECT 0) t53, (SELECT 0) t54, (SELECT 0) t55,
(SELECT 0) t56, (SELECT 0) t57, (SELECT 0) t58, (SELECT 0) t59, (SELECT 0) t60,
(SELECT 0) t61;
0
0
#
# A nested materialized derived table is used before being populated.
# (addon for bug#19077)
#
CREATE TABLE t1 (i INT, j BIGINT);
INSERT INTO t1 VALUES (1, 2), (2, 2), (3, 2);
SELECT * FROM (SELECT MIN(i) FROM t1
WHERE j = SUBSTRING('12', (SELECT * FROM (SELECT MIN(j) FROM t1) t2))) t3;
MIN(i)
1
DROP TABLE t1;
# End of 5.0 tests
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