set optimizer_switch='index_condition_pushdown=on,mrr=on,mrr_cost_based=off';
drop table if exists t1,t2,t3;
CREATE TABLE t1 (
id int(6) DEFAULT '0' NOT NULL,
idservice int(5),
clee char(20) NOT NULL,
flag char(1),
KEY id (id),
PRIMARY KEY (clee)
);
INSERT INTO t1 VALUES (2,4,'6067169d','Y');
INSERT INTO t1 VALUES (2,5,'606716d1','Y');
INSERT INTO t1 VALUES (2,1,'606717c1','Y');
INSERT INTO t1 VALUES (3,1,'6067178d','Y');
INSERT INTO t1 VALUES (2,6,'60671515','Y');
INSERT INTO t1 VALUES (2,7,'60671569','Y');
INSERT INTO t1 VALUES (2,3,'dd','Y');
CREATE TABLE t2 (
id int(6) NOT NULL auto_increment,
description varchar(40) NOT NULL,
idform varchar(40),
ordre int(6) unsigned DEFAULT '0' NOT NULL,
image varchar(60),
PRIMARY KEY (id),
KEY id (id,ordre)
);
INSERT INTO t2 VALUES (1,'Emettre un appel d''offres','en_construction.html',10,'emettre.gif');
INSERT INTO t2 VALUES (2,'Emettre des soumissions','en_construction.html',20,'emettre.gif');
INSERT INTO t2 VALUES (7,'Liste des t2','t2_liste_form.phtml',51060,'link.gif');
INSERT INTO t2 VALUES (8,'Consulter les soumissions','consulter_soumissions.phtml',200,'link.gif');
INSERT INTO t2 VALUES (9,'Ajouter un type de materiel','typeMateriel_ajoute_form.phtml',51000,'link.gif');
INSERT INTO t2 VALUES (10,'Lister/modifier un type de materiel','typeMateriel_liste_form.phtml',51010,'link.gif');
INSERT INTO t2 VALUES (3,'Créer une fiche de client','clients_ajoute_form.phtml',40000,'link.gif');
INSERT INTO t2 VALUES (4,'Modifier des clients','en_construction.html',40010,'link.gif');
INSERT INTO t2 VALUES (5,'Effacer des clients','en_construction.html',40020,'link.gif');
INSERT INTO t2 VALUES (6,'Ajouter un service','t2_ajoute_form.phtml',51050,'link.gif');
select t1.id,t1.idservice,t2.ordre,t2.description from t1, t2 where t1.id = 2 and t1.idservice = t2.id order by t2.ordre;
id idservice ordre description
2 1 10 Emettre un appel d'offres
2 3 40000 Créer une fiche de client
2 4 40010 Modifier des clients
2 5 40020 Effacer des clients
2 6 51050 Ajouter un service
2 7 51060 Liste des t2
drop table t1,t2;
create table t1 (first char(10),last char(10));
insert into t1 values ("Michael","Widenius");
insert into t1 values ("Allan","Larsson");
insert into t1 values ("David","Axmark");
select concat(first," ",last) as name from t1 order by name;
name
Allan Larsson
David Axmark
Michael Widenius
select concat(last," ",first) as name from t1 order by name;
name
Axmark David
Larsson Allan
Widenius Michael
drop table t1;
create table t1 (i int);
insert into t1 values(1),(2),(1),(2),(1),(2),(3);
select distinct i from t1;
i
1
2
3
select distinct i from t1 order by rand(5);
i
1
3
2
select distinct i from t1 order by i desc;
i
3
2
1
select distinct i from t1 order by 1-i;
i
3
2
1
select distinct i from t1 order by mod(i,2),i;
i
2
1
3
drop table t1;
create table t1 ( pk int primary key, name varchar(255) not null, number varchar(255) not null);
insert into t1 values (1, 'Gamma', '123'), (2, 'Gamma Ext', '123a'), (3, 'Alpha', '001'), (4, 'Beta', '200c');
select distinct t1.name as 'Building Name',t1.number as 'Building Number' from t1 order by t1.name asc;
Building Name Building Number
Alpha 001
Beta 200c
Gamma 123
Gamma Ext 123a
drop table t1;
create table t1 (id int not null,col1 int not null,col2 int not null,index(col1));
insert into t1 values(1,2,2),(2,2,1),(3,1,2),(4,1,1),(5,1,4),(6,2,3),(7,3,1),(8,2,4);
select * from t1 order by col1,col2;
id col1 col2
4 1 1
3 1 2
5 1 4
2 2 1
1 2 2
6 2 3
8 2 4
7 3 1
select col1 from t1 order by id;
col1
2
2
1
1
1
2
3
2
select col1 as id from t1 order by id;
id
1
1
1
2
2
2
2
3
select concat(col1) as id from t1 order by id;
id
1
1
1
2
2
2
2
3
drop table t1;
CREATE TABLE t1 (id int auto_increment primary key,aika varchar(40),aikakentta timestamp);
insert into t1 (aika) values ('Keskiviikko');
insert into t1 (aika) values ('Tiistai');
insert into t1 (aika) values ('Maanantai');
insert into t1 (aika) values ('Sunnuntai');
SELECT FIELD(SUBSTRING(t1.aika,1,2),'Ma','Ti','Ke','To','Pe','La','Su') AS test FROM t1 ORDER by test;
test
1
2
3
7
drop table t1;
CREATE TABLE t1
(
a int unsigned NOT NULL,
b int unsigned NOT NULL,
c int unsigned NOT NULL,
UNIQUE(a),
INDEX(b),
INDEX(c)
);
CREATE TABLE t2
(
c int unsigned NOT NULL,
i int unsigned NOT NULL,
INDEX(c)
);
CREATE TABLE t3
(
c int unsigned NOT NULL,
v varchar(64),
INDEX(c)
);
INSERT INTO t1 VALUES (1,1,1);
INSERT INTO t1 VALUES (2,1,2);
INSERT INTO t1 VALUES (3,2,1);
INSERT INTO t1 VALUES (4,2,2);
INSERT INTO t2 VALUES (1,50);
INSERT INTO t2 VALUES (2,25);
INSERT INTO t3 VALUES (1,'123 Park Place');
INSERT INTO t3 VALUES (2,'453 Boardwalk');
SELECT a,b,if(b = 1,i,if(b = 2,v,''))
FROM t1
LEFT JOIN t2 USING(c)
LEFT JOIN t3 ON t3.c = t1.c;
a b if(b = 1,i,if(b = 2,v,''))
1 1 50
3 2 123 Park Place
2 1 25
4 2 453 Boardwalk
SELECT a,b,if(b = 1,i,if(b = 2,v,''))
FROM t1
LEFT JOIN t2 ON t1.c = t2.c
LEFT JOIN t3 ON t3.c = t1.c;
a b if(b = 1,i,if(b = 2,v,''))
1 1 50
3 2 123 Park Place
2 1 25
4 2 453 Boardwalk
SELECT a,b,if(b = 1,i,if(b = 2,v,''))
FROM t1
LEFT JOIN t2 USING(c)
LEFT JOIN t3 ON t3.c = t1.c
ORDER BY a;
a b if(b = 1,i,if(b = 2,v,''))
1 1 50
2 1 25
3 2 123 Park Place
4 2 453 Boardwalk
SELECT a,b,if(b = 1,i,if(b = 2,v,''))
FROM t1
LEFT JOIN t2 ON t1.c = t2.c
LEFT JOIN t3 ON t3.c = t1.c
ORDER BY a;
a b if(b = 1,i,if(b = 2,v,''))
1 1 50
2 1 25
3 2 123 Park Place
4 2 453 Boardwalk
drop table t1,t2,t3;
create table t1 (ID int not null primary key, TransactionID int not null);
insert into t1 (ID, TransactionID) values (1, 87), (2, 89), (3, 92), (4, 94), (5, 486), (6, 490), (7, 753), (9, 828), (10, 832), (11, 834), (12, 840);
create table t2 (ID int not null primary key, GroupID int not null);
insert into t2 (ID, GroupID) values (87, 87), (89, 89), (92, 92), (94, 94), (486, 486), (490, 490),(753, 753), (828, 828), (832, 832), (834, 834), (840, 840);
create table t3 (ID int not null primary key, DateOfAction date not null);
insert into t3 (ID, DateOfAction) values (87, '1999-07-19'), (89, '1999-07-19'), (92, '1999-07-19'), (94, '1999-07-19'), (486, '1999-07-18'), (490, '2000-03-27'), (753, '2000-03-28'), (828, '1999-07-27'), (832, '1999-07-27'),(834, '1999-07-27'), (840, '1999-07-27');
select t3.DateOfAction, t1.TransactionID from t1 join t2 join t3 where t2.ID = t1.TransactionID and t3.ID = t2.GroupID order by t3.DateOfAction, t1.TransactionID;
DateOfAction TransactionID
1999-07-18 486
1999-07-19 87
1999-07-19 89
1999-07-19 92
1999-07-19 94
1999-07-27 828
1999-07-27 832
1999-07-27 834
1999-07-27 840
2000-03-27 490
2000-03-28 753
select t3.DateOfAction, t1.TransactionID from t1 join t2 join t3 where t2.ID = t1.TransactionID and t3.ID = t2.GroupID order by t1.TransactionID,t3.DateOfAction;
DateOfAction TransactionID
1999-07-19 87
1999-07-19 89
1999-07-19 92
1999-07-19 94
1999-07-18 486
2000-03-27 490
2000-03-28 753
1999-07-27 828
1999-07-27 832
1999-07-27 834
1999-07-27 840
drop table t1,t2,t3;
CREATE TABLE t1 (
member_id int(11) NOT NULL auto_increment,
inschrijf_datum varchar(20) NOT NULL default '',
lastchange_datum varchar(20) NOT NULL default '',
nickname varchar(20) NOT NULL default '',
password varchar(8) NOT NULL default '',
voornaam varchar(30) NOT NULL default '',
tussenvoegsels varchar(10) NOT NULL default '',
achternaam varchar(50) NOT NULL default '',
straat varchar(100) NOT NULL default '',
postcode varchar(10) NOT NULL default '',
wijk varchar(40) NOT NULL default '',
plaats varchar(50) NOT NULL default '',
telefoon varchar(10) NOT NULL default '',
geboortedatum date NOT NULL default '0000-00-00',
geslacht varchar(5) NOT NULL default '',
email varchar(80) NOT NULL default '',
uin varchar(15) NOT NULL default '',
homepage varchar(100) NOT NULL default '',
internet varchar(15) NOT NULL default '',
scherk varchar(30) NOT NULL default '',
favo_boek varchar(50) NOT NULL default '',
favo_tijdschrift varchar(50) NOT NULL default '',
favo_tv varchar(50) NOT NULL default '',
favo_eten varchar(50) NOT NULL default '',
favo_muziek varchar(30) NOT NULL default '',
info text NOT NULL default '',
ipnr varchar(30) NOT NULL default '',
PRIMARY KEY (member_id)
) ENGINE=MyISAM PACK_KEYS=1;
Warnings:
Warning 1101 BLOB/TEXT column 'info' can't have a default value
insert into t1 (member_id) values (1),(2),(3);
select member_id, nickname, voornaam FROM t1
ORDER by lastchange_datum DESC LIMIT 2;
member_id nickname voornaam
1
2
drop table t1;
create table t1 (a int not null, b int, c varchar(10), key (a, b, c));
insert into t1 values (1, NULL, NULL), (1, NULL, 'b'), (1, 1, NULL), (1, 1, 'b'), (1, 1, 'b'), (2, 1, 'a'), (2, 1, 'b'), (2, 2, 'a'), (2, 2, 'b'), (2, 3, 'c'),(1,3,'b');
explain select * from t1 where (a = 1 and b is null and c = 'b') or (a > 2) order by a desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index a a 22 NULL 11 Using where; Using index
select * from t1 where (a = 1 and b is null and c = 'b') or (a > 2) order by a desc;
a b c
1 NULL b
explain select * from t1 where a >= 1 and a < 3 order by a desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 4 NULL 10 Using where; Using index
select * from t1 where a >= 1 and a < 3 order by a desc;
a b c
2 3 c
2 2 b
2 2 a
2 1 b
2 1 a
1 3 b
1 1 b
1 1 b
1 1 NULL
1 NULL b
1 NULL NULL
explain select * from t1 where a = 1 order by a desc, b desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref a a 4 const 5 Using where; Using index
select * from t1 where a = 1 order by a desc, b desc;
a b c
1 3 b
1 1 b
1 1 b
1 1 NULL
1 NULL b
1 NULL NULL
explain select * from t1 where a = 1 and b is null order by a desc, b desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref a a 9 const,const 2 Using where; Using index; Using filesort
select * from t1 where a = 1 and b is null order by a desc, b desc;
a b c
1 NULL NULL
1 NULL b
explain select * from t1 where a >= 1 and a < 3 and b >0 order by a desc,b desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 9 NULL 8 Using where; Using index
explain select * from t1 where a = 2 and b >0 order by a desc,b desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 9 NULL 5 Using where; Using index
explain select * from t1 where a = 2 and b is null order by a desc,b desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref a a 9 const,const 1 Using where; Using index; Using filesort
explain select * from t1 where a = 2 and (b is null or b > 0) order by a
desc,b desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 9 NULL 6 Using where; Using index
explain select * from t1 where a = 2 and b > 0 order by a desc,b desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 9 NULL 5 Using where; Using index
explain select * from t1 where a = 2 and b < 2 order by a desc,b desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 9 NULL 2 Using where; Using index
explain select * from t1 where a = 1 order by b desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref a a 4 const 5 Using where; Using index
select * from t1 where a = 1 order by b desc;
a b c
1 3 b
1 1 b
1 1 b
1 1 NULL
1 NULL b
1 NULL NULL
alter table t1 modify b int not null, modify c varchar(10) not null;
Warnings:
Warning 1265 Data truncated for column 'b' at row 1
Warning 1265 Data truncated for column 'c' at row 1
Warning 1265 Data truncated for column 'b' at row 2
Warning 1265 Data truncated for column 'c' at row 3
explain select * from t1 order by a, b, c;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL a 20 NULL 11 Using index
select * from t1 order by a, b, c;
a b c
1 0
1 0 b
1 1
1 1 b
1 1 b
1 3 b
2 1 a
2 1 b
2 2 a
2 2 b
2 3 c
explain select * from t1 order by a desc, b desc, c desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL a 20 NULL 11 Using index
select * from t1 order by a desc, b desc, c desc;
a b c
2 3 c
2 2 b
2 2 a
2 1 b
2 1 a
1 3 b
1 1 b
1 1 b
1 1
1 0 b
1 0
explain select * from t1 where (a = 1 and b = 1 and c = 'b') or (a > 2) order by a desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 20 NULL 3 Using where; Using index
select * from t1 where (a = 1 and b = 1 and c = 'b') or (a > 2) order by a desc;
a b c
1 1 b
1 1 b
explain select * from t1 where a < 2 and b <= 1 order by a desc, b desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 4 NULL 6 Using where; Using index
select * from t1 where a < 2 and b <= 1 order by a desc, b desc;
a b c
1 1 b
1 1 b
1 1
1 0 b
1 0
select count(*) from t1 where a < 5 and b > 0;
count(*)
9
select * from t1 where a < 5 and b > 0 order by a desc,b desc;
a b c
2 3 c
2 2 b
2 2 a
2 1 b
2 1 a
1 3 b
1 1 b
1 1 b
1 1
explain select * from t1 where a between 1 and 3 and b <= 1 order by a desc, b desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 8 NULL 10 Using where; Using index
select * from t1 where a between 1 and 3 and b <= 1 order by a desc, b desc;
a b c
2 1 b
2 1 a
1 1 b
1 1 b
1 1
1 0 b
1 0
explain select * from t1 where a between 0 and 1 order by a desc, b desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 4 NULL 5 Using where; Using index
select * from t1 where a between 0 and 1 order by a desc, b desc;
a b c
1 3 b
1 1 b
1 1 b
1 1
1 0 b
1 0
drop table t1;
CREATE TABLE t1 (
gid int(10) unsigned NOT NULL auto_increment,
cid smallint(5) unsigned NOT NULL default '0',
PRIMARY KEY (gid),
KEY component_id (cid)
) ENGINE=MyISAM;
INSERT INTO t1 VALUES (103853,108),(103867,108),(103962,108),(104505,108),(104619,108),(104620,108);
ALTER TABLE t1 add skr int(10) not null;
CREATE TABLE t2 (
gid int(10) unsigned NOT NULL default '0',
uid smallint(5) unsigned NOT NULL default '1',
sid tinyint(3) unsigned NOT NULL default '1',
PRIMARY KEY (gid),
KEY uid (uid),
KEY status_id (sid)
) ENGINE=MyISAM;
INSERT INTO t2 VALUES (103853,250,5),(103867,27,5),(103962,27,5),(104505,117,5),(104619,75,5),(104620,15,5);
CREATE TABLE t3 (
uid smallint(6) NOT NULL auto_increment,
PRIMARY KEY (uid)
) ENGINE=MyISAM;
INSERT INTO t3 VALUES (1),(15),(27),(75),(117),(250);
ALTER TABLE t3 add skr int(10) not null;
select t1.gid, t2.sid, t3.uid from t2, t1, t3 where t2.gid = t1.gid and t2.uid = t3.uid order by t3.uid, t1.gid;
gid sid uid
104620 5 15
103867 5 27
103962 5 27
104619 5 75
104505 5 117
103853 5 250
select t1.gid, t2.sid, t3.uid from t3, t2, t1 where t2.gid = t1.gid and t2.uid = t3.uid order by t3.uid, t1.gid;
gid sid uid
104620 5 15
103867 5 27
103962 5 27
104619 5 75
104505 5 117
103853 5 250
EXPLAIN select t1.gid, t2.sid, t3.uid from t3, t2, t1 where t2.gid = t1.gid and t2.uid = t3.uid order by t1.gid, t3.uid;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ALL PRIMARY,uid NULL NULL NULL 6 Using temporary; Using filesort
1 SIMPLE t3 eq_ref PRIMARY PRIMARY 2 test.t2.uid 1 Using where; Using index
1 SIMPLE t1 eq_ref PRIMARY PRIMARY 4 test.t2.gid 1 Using index
EXPLAIN SELECT t1.gid, t3.uid from t1, t3 where t1.gid = t3.uid order by t1.gid,t3.skr;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t3 ALL PRIMARY NULL NULL NULL 6 Using temporary; Using filesort
1 SIMPLE t1 eq_ref PRIMARY PRIMARY 4 test.t3.uid 1 Using where; Using index
EXPLAIN SELECT t1.gid, t2.sid, t3.uid from t2, t1, t3 where t2.gid = t1.gid and t2.uid = t3.uid order by t3.uid, t1.gid;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ALL PRIMARY,uid NULL NULL NULL 6 Using temporary; Using filesort
1 SIMPLE t1 eq_ref PRIMARY PRIMARY 4 test.t2.gid 1 Using index
1 SIMPLE t3 eq_ref PRIMARY PRIMARY 2 test.t2.uid 1 Using where; Using index
EXPLAIN SELECT t1.gid, t3.uid from t1, t3 where t1.gid = t3.uid order by t3.skr,t1.gid;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t3 ALL PRIMARY NULL NULL NULL 6 Using temporary; Using filesort
1 SIMPLE t1 eq_ref PRIMARY PRIMARY 4 test.t3.uid 1 Using where; Using index
EXPLAIN SELECT t1.gid, t3.uid from t1, t3 where t1.skr = t3.uid order by t1.gid,t3.skr;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 6 Using temporary; Using filesort
1 SIMPLE t3 eq_ref PRIMARY PRIMARY 2 test.t1.skr 1 Using index condition
drop table t1,t2,t3;
CREATE TABLE t1 (
`titre` char(80) NOT NULL default '',
`numeropost` mediumint(8) unsigned NOT NULL auto_increment,
`date` datetime NOT NULL default '0000-00-00 00:00:00',
`auteur` char(35) NOT NULL default '',
`icone` tinyint(2) unsigned NOT NULL default '0',
`lastauteur` char(35) NOT NULL default '',
`nbrep` smallint(6) unsigned NOT NULL default '0',
`dest` char(35) NOT NULL default '',
`lu` tinyint(1) unsigned NOT NULL default '0',
`vue` mediumint(8) unsigned NOT NULL default '0',
`ludest` tinyint(1) unsigned NOT NULL default '0',
`ouvert` tinyint(1) unsigned NOT NULL default '1',
PRIMARY KEY (`numeropost`),
KEY `date` (`date`),
KEY `dest` (`dest`,`ludest`),
KEY `auteur` (`auteur`,`lu`),
KEY `auteur_2` (`auteur`,`date`),
KEY `dest_2` (`dest`,`date`)
) CHECKSUM=1;
CREATE TABLE t2 (
`numeropost` mediumint(8) unsigned NOT NULL default '0',
`pseudo` char(35) NOT NULL default '',
PRIMARY KEY (`numeropost`,`pseudo`),
KEY `pseudo` (`pseudo`)
);
INSERT INTO t1 (titre,auteur,dest) VALUES ('test','joce','bug');
INSERT INTO t2 (numeropost,pseudo) VALUES (1,'joce'),(1,'bug');
SELECT titre,t1.numeropost,auteur,icone,nbrep,0,date,vue,ouvert,lastauteur,dest FROM t2 LEFT JOIN t1 USING(numeropost) WHERE t2.pseudo='joce' ORDER BY date DESC LIMIT 0,30;
titre numeropost auteur icone nbrep 0 date vue ouvert lastauteur dest
test 1 joce 0 0 0 0000-00-00 00:00:00 0 1 bug
SELECT titre,numeropost,auteur,icone,nbrep,0,date,vue,ouvert,lastauteur,dest FROM t2 LEFT JOIN t1 USING(numeropost) WHERE t2.pseudo='joce' ORDER BY date DESC LIMIT 0,30;
titre numeropost auteur icone nbrep 0 date vue ouvert lastauteur dest
test 1 joce 0 0 0 0000-00-00 00:00:00 0 1 bug
SELECT titre,t1.numeropost,auteur,icone,nbrep,'0',date,vue,ouvert,lastauteur,dest FROM t2 LEFT JOIN t1 USING(numeropost) WHERE t2.pseudo='joce' ORDER BY date DESC LIMIT 0,30;
titre numeropost auteur icone nbrep 0 date vue ouvert lastauteur dest
test 1 joce 0 0 0 0000-00-00 00:00:00 0 1 bug
SELECT titre,numeropost,auteur,icone,nbrep,'0',date,vue,ouvert,lastauteur,dest FROM t2 LEFT JOIN t1 USING(numeropost) WHERE t2.pseudo='joce' ORDER BY date DESC LIMIT 0,30;
titre numeropost auteur icone nbrep 0 date vue ouvert lastauteur dest
test 1 joce 0 0 0 0000-00-00 00:00:00 0 1 bug
drop table t1,t2;
CREATE TABLE t1 (a int, b int);
INSERT INTO t1 VALUES (1, 2);
INSERT INTO t1 VALUES (3, 4);
INSERT INTO t1 VALUES (5, NULL);
SELECT * FROM t1 ORDER BY b;
a b
5 NULL
1 2
3 4
SELECT * FROM t1 ORDER BY b DESC;
a b
3 4
1 2
5 NULL
SELECT * FROM t1 ORDER BY (a + b);
a b
5 NULL
1 2
3 4
SELECT * FROM t1 ORDER BY (a + b) DESC;
a b
3 4
1 2
5 NULL
DROP TABLE t1;
create table t1(id int not null auto_increment primary key, t char(12));
explain select id,t from t1 order by id;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 1000 Using filesort
explain select id,t from t1 force index (primary) order by id;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL PRIMARY 4 NULL 1000 NULL
drop table t1;
CREATE TABLE t1 (
FieldKey varchar(36) NOT NULL default '',
LongVal bigint(20) default NULL,
StringVal mediumtext,
KEY FieldKey (FieldKey),
KEY LongField (FieldKey,LongVal),
KEY StringField (FieldKey,StringVal(32))
);
INSERT INTO t1 VALUES ('0',3,'0'),('0',2,'1'),('0',1,'2'),('1',2,'1'),('1',1,'3'), ('1',0,'2'),('2',3,'0'),('2',2,'1'),('2',1,'2'),('2',3,'0'),('2',2,'1'),('2',1,'2'),('3',2,'1'),('3',1,'2'),('3','3','3');
EXPLAIN SELECT * FROM t1 WHERE FieldKey = '1' ORDER BY LongVal;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref FieldKey,LongField,StringField LongField 38 const 3 Using where
SELECT * FROM t1 WHERE FieldKey = '1' ORDER BY LongVal;
FieldKey LongVal StringVal
1 0 2
1 1 3
1 2 1
EXPLAIN SELECT * FROM t1 ignore index (FieldKey, LongField) WHERE FieldKey > '2' ORDER BY LongVal;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range StringField StringField 38 NULL 4 Using where; Using filesort
SELECT * FROM t1 WHERE FieldKey > '2' ORDER BY LongVal;
FieldKey LongVal StringVal
3 1 2
3 2 1
3 3 3
EXPLAIN SELECT * FROM t1 WHERE FieldKey > '2' ORDER BY FieldKey, LongVal;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range FieldKey,LongField,StringField LongField 38 NULL 4 Using where
SELECT * FROM t1 WHERE FieldKey > '2' ORDER BY FieldKey, LongVal;
FieldKey LongVal StringVal
3 1 2
3 2 1
3 3 3
DROP TABLE t1;
CREATE TABLE t1 (a INT, b INT);
SET @id=0;
UPDATE t1 SET a=0 ORDER BY (a=@id), b;
DROP TABLE t1;
CREATE TABLE t1 ( id smallint(6) unsigned NOT NULL default '0', menu tinyint(4) NOT NULL default '0', KEY id (id), KEY menu (menu)) ENGINE=MyISAM;
INSERT INTO t1 VALUES (11384, 2),(11392, 2);
SELECT id FROM t1 WHERE id <11984 AND menu =2 ORDER BY id DESC LIMIT 1 ;
id
11392
drop table t1;
create table t1(a int, b int, index(b));
insert into t1 values (2, 1), (1, 1), (4, NULL), (3, NULL), (6, 2), (5, 2);
explain select * from t1 where b=1 or b is null order by a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref_or_null b b 5 const 3 Using index condition; Using filesort
select * from t1 where b=1 or b is null order by a;
a b
1 1
2 1
3 NULL
4 NULL
explain select * from t1 where b=2 or b is null order by a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref_or_null b b 5 const 4 Using index condition; Using filesort
select * from t1 where b=2 or b is null order by a;
a b
3 NULL
4 NULL
5 2
6 2
drop table t1;
create table t1 (a int not null auto_increment, b int not null, c int not null, d int not null,
key(a,b,d), key(c,b,a));
create table t2 like t1;
insert into t1 values (NULL, 1, 2, 0), (NULL, 2, 1, 1), (NULL, 3, 4, 2), (NULL, 4, 3, 3);
insert into t2 select null, b, c, d from t1;
insert into t1 select null, b, c, d from t2;
insert into t2 select null, b, c, d from t1;
insert into t1 select null, b, c, d from t2;
insert into t2 select null, b, c, d from t1;
insert into t1 select null, b, c, d from t2;
insert into t2 select null, b, c, d from t1;
insert into t1 select null, b, c, d from t2;
insert into t2 select null, b, c, d from t1;
insert into t1 select null, b, c, d from t2;
optimize table t1;
Table Op Msg_type Msg_text
test.t1 optimize status OK
set @row=10;
insert into t1 select 1, b, c + (@row:=@row - 1) * 10, d - @row from t2 limit 10;
select * from t1 where a=1 and b in (1) order by c, b, a;
a b c d
1 1 2 0
1 1 12 -1
1 1 52 -5
1 1 92 -9
select * from t1 where a=1 and b in (1);
a b c d
1 1 92 -9
1 1 52 -5
1 1 12 -1
1 1 2 0
drop table t1, t2;
create table t1 (col1 int, col int);
create table t2 (col2 int, col int);
insert into t1 values (1,1),(2,2),(3,3);
insert into t2 values (1,3),(2,2),(3,1);
select t1.* , t2.col as t2_col from t1 left join t2 on (t1.col1=t2.col2)
order by col;
col1 col t2_col
1 1 3
2 2 2
3 3 1
select col1 as col, col from t1 order by col;
ERROR 23000: Column 'col' in order clause is ambiguous
select t1.col as c1, t2.col as c2 from t1, t2 where t1.col1=t2.col2
order by col;
ERROR 23000: Column 'col' in order clause is ambiguous
select t1.col as c1, t2.col as c2 from t1, t2 where t1.col1=t2.col2
order by col;
ERROR 23000: Column 'col' in order clause is ambiguous
select col1 from t1, t2 where t1.col1=t2.col2 order by col;
ERROR 23000: Column 'col' in order clause is ambiguous
select t1.col as t1_col, t2.col2 from t1, t2 where t1.col1=t2.col2
order by col;
ERROR 23000: Column 'col' in order clause is ambiguous
select t1.col as t1_col, t2.col from t1, t2 where t1.col1=t2.col2
order by col;
t1_col col
3 1
2 2
1 3
select col2 as c, col as c from t2 order by col;
c c
3 1
2 2
1 3
select col2 as col, col as col2 from t2 order by col;
col col2
1 3
2 2
3 1
select t2.col2, t2.col, t2.col from t2 order by col;
col2 col col
3 1 1
2 2 2
1 3 3
select t2.col2 as col from t2 order by t2.col;
col
3
2
1
select t2.col2 as col, t2.col from t2 order by t2.col;
col col
3 1
2 2
1 3
select t2.col2, t2.col, t2.col from t2 order by t2.col;
col2 col col
3 1 1
2 2 2
1 3 3
drop table t1, t2;
create table t1 (a char(25));
insert into t1 set a = repeat('x', 20);
insert into t1 set a = concat(repeat('x', 19), 'z');
insert into t1 set a = concat(repeat('x', 19), 'ab');
insert into t1 set a = concat(repeat('x', 19), 'aa');
set max_sort_length=20;
select a from t1 order by a;
a
xxxxxxxxxxxxxxxxxxxab
xxxxxxxxxxxxxxxxxxxaa
xxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxz
drop table t1;
create table t1 (
`sid` decimal(8,0) default null,
`wnid` varchar(11) not null default '',
key `wnid14` (`wnid`(4)),
key `wnid` (`wnid`)
) engine=myisam default charset=latin1;
insert into t1 (`sid`, `wnid`) values
('10100','01019000000'),('37986','01019000000'),('37987','01019010000'),
('39560','01019090000'),('37989','01019000000'),('37990','01019011000'),
('37991','01019011000'),('37992','01019019000'),('37993','01019030000'),
('37994','01019090000'),('475','02070000000'),('25253','02071100000'),
('25255','02071100000'),('25256','02071110000'),('25258','02071130000'),
('25259','02071190000'),('25260','02071200000'),('25261','02071210000'),
('25262','02071290000'),('25263','02071300000'),('25264','02071310000'),
('25265','02071310000'),('25266','02071320000'),('25267','02071320000'),
('25269','02071330000'),('25270','02071340000'),('25271','02071350000'),
('25272','02071360000'),('25273','02071370000'),('25281','02071391000'),
('25282','02071391000'),('25283','02071399000'),('25284','02071400000'),
('25285','02071410000'),('25286','02071410000'),('25287','02071420000'),
('25288','02071420000'),('25291','02071430000'),('25290','02071440000'),
('25292','02071450000'),('25293','02071460000'),('25294','02071470000'),
('25295','02071491000'),('25296','02071491000'),('25297','02071499000');
explain select * from t1 where wnid like '0101%' order by wnid;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range wnid14,wnid wnid 13 NULL 10 Using index condition
select * from t1 where wnid like '0101%' order by wnid;
sid wnid
10100 01019000000
37986 01019000000
37989 01019000000
37987 01019010000
37990 01019011000
37991 01019011000
37992 01019019000
37993 01019030000
39560 01019090000
37994 01019090000
drop table t1;
CREATE TABLE t1 (a int);
INSERT INTO t1 VALUES (2), (1), (1), (2), (1);
SELECT a FROM t1 ORDER BY a;
a
1
1
1
2
2
(SELECT a FROM t1) ORDER BY a;
a
1
1
1
2
2
DROP TABLE t1;
CREATE TABLE t1 (a int, b int);
INSERT INTO t1 VALUES (1,30), (2,20), (1,10), (2,30), (1,20), (2,10);
(SELECT b,a FROM t1 ORDER BY a,b) ORDER BY b,a;
b a
10 1
10 2
20 1
20 2
30 1
30 2
(SELECT b FROM t1 ORDER BY b DESC) ORDER BY b ASC;
b
10
10
20
20
30
30
(SELECT b,a FROM t1 ORDER BY b,a) ORDER BY a,b;
b a
10 1
20 1
30 1
10 2
20 2
30 2
(SELECT b,a FROM t1 ORDER by b,a LIMIT 3) ORDER by a,b;
b a
10 1
20 1
10 2
DROP TABLE t1;
CREATE TABLE t1 (a INT);
INSERT INTO t1 VALUES (1),(2);
SELECT a + 1 AS num FROM t1 ORDER BY 30 - num;
num
3
2
SELECT CONCAT('test', a) AS str FROM t1 ORDER BY UPPER(str);
str
test1
test2
SELECT a + 1 AS num FROM t1 GROUP BY 30 - num;
num
3
2
SELECT a + 1 AS num FROM t1 HAVING 30 - num;
num
2
3
SELECT a + 1 AS num, num + 1 FROM t1;
ERROR 42S22: Unknown column 'num' in 'field list'
SELECT a + 1 AS num, (select num + 2 FROM t1 LIMIT 1) FROM t1;
num (select num + 2 FROM t1 LIMIT 1)
2 4
3 5
SELECT a.a + 1 AS num FROM t1 a JOIN t1 b ON num = b.a;
ERROR 42S22: Unknown column 'num' in 'on clause'
DROP TABLE t1;
CREATE TABLE bug25126 (
val int unsigned NOT NULL AUTO_INCREMENT PRIMARY KEY
);
UPDATE bug25126 SET MissingCol = MissingCol;
ERROR 42S22: Unknown column 'MissingCol' in 'field list'
UPDATE bug25126 SET val = val ORDER BY MissingCol;
ERROR 42S22: Unknown column 'MissingCol' in 'order clause'
UPDATE bug25126 SET val = val ORDER BY val;
UPDATE bug25126 SET val = 1 ORDER BY val;
UPDATE bug25126 SET val = 1 ORDER BY MissingCol;
ERROR 42S22: Unknown column 'MissingCol' in 'order clause'
UPDATE bug25126 SET val = 1 ORDER BY val, MissingCol;
ERROR 42S22: Unknown column 'MissingCol' in 'order clause'
UPDATE bug25126 SET val = MissingCol ORDER BY MissingCol;
ERROR 42S22: Unknown column 'MissingCol' in 'order clause'
UPDATE bug25126 SET MissingCol = 1 ORDER BY val, MissingCol;
ERROR 42S22: Unknown column 'MissingCol' in 'order clause'
UPDATE bug25126 SET MissingCol = 1 ORDER BY MissingCol;
ERROR 42S22: Unknown column 'MissingCol' in 'order clause'
UPDATE bug25126 SET MissingCol = val ORDER BY MissingCol;
ERROR 42S22: Unknown column 'MissingCol' in 'order clause'
UPDATE bug25126 SET MissingCol = MissingCol ORDER BY MissingCol;
ERROR 42S22: Unknown column 'MissingCol' in 'order clause'
DROP TABLE bug25126;
CREATE TABLE t1 (a int);
SELECT p.a AS val, q.a AS val1 FROM t1 p, t1 q ORDER BY val > 1;
val val1
SELECT p.a AS val, q.a AS val FROM t1 p, t1 q ORDER BY val;
ERROR 23000: Column 'val' in order clause is ambiguous
SELECT p.a AS val, q.a AS val FROM t1 p, t1 q ORDER BY val > 1;
ERROR 23000: Column 'val' in order clause is ambiguous
DROP TABLE t1;
CREATE TABLE t1 (a int);
INSERT INTO t1 VALUES (3), (2), (4), (1);
SELECT a, IF(a IN (2,3), a, a+10) FROM t1
ORDER BY IF(a IN (2,3), a, a+10);
a IF(a IN (2,3), a, a+10)
2 2
3 3
1 11
4 14
SELECT a, IF(a NOT IN (2,3), a, a+10) FROM t1
ORDER BY IF(a NOT IN (2,3), a, a+10);
a IF(a NOT IN (2,3), a, a+10)
1 1
4 4
2 12
3 13
SELECT a, IF(a IN (2,3), a, a+10) FROM t1
ORDER BY IF(a NOT IN (2,3), a, a+10);
a IF(a IN (2,3), a, a+10)
1 11
4 14
2 2
3 3
SELECT a, IF(a BETWEEN 2 AND 3, a, a+10) FROM t1
ORDER BY IF(a BETWEEN 2 AND 3, a, a+10);
a IF(a BETWEEN 2 AND 3, a, a+10)
2 2
3 3
1 11
4 14
SELECT a, IF(a NOT BETWEEN 2 AND 3, a, a+10) FROM t1
ORDER BY IF(a NOT BETWEEN 2 AND 3, a, a+10);
a IF(a NOT BETWEEN 2 AND 3, a, a+10)
1 1
4 4
2 12
3 13
SELECT a, IF(a BETWEEN 2 AND 3, a, a+10) FROM t1
ORDER BY IF(a NOT BETWEEN 2 AND 3, a, a+10);
a IF(a BETWEEN 2 AND 3, a, a+10)
1 11
4 14
2 2
3 3
SELECT IF(a IN (1,2), a, '') as x1, IF(a NOT IN (1,2), a, '') as x2
FROM t1 GROUP BY x1, x2;
x1 x2
3
4
1
2
SELECT IF(a IN (1,2), a, '') as x1, IF(a NOT IN (1,2), a, '') as x2
FROM t1 GROUP BY x1, IF(a NOT IN (1,2), a, '');
x1 x2
3
4
1
2
SELECT a, a IN (1,2) FROM t1 ORDER BY a IN (1,2);
a a IN (1,2)
3 0
4 0
2 1
1 1
SELECT a FROM t1 ORDER BY a IN (1,2);
a
3
4
2
1
SELECT a+10 FROM t1 ORDER BY a IN (1,2);
a+10
13
14
12
11
SELECT a, IF(a IN (1,2), a, a+10) FROM t1
ORDER BY IF(a IN (3,4), a, a+10);
a IF(a IN (1,2), a, a+10)
3 13
4 14
1 1
2 2
DROP TABLE t1;
create table t1 (a int not null, b int not null, c int not null);
insert t1 values (1,1,1),(1,1,2),(1,2,1);
select a, b from t1 group by a, b order by sum(c);
a b
1 2
1 1
drop table t1;
CREATE TABLE t1 (a int, b int, PRIMARY KEY (a));
INSERT INTO t1 VALUES (1,1), (2,2), (3,3);
explain SELECT t1.b as a, t2.b as c FROM
t1 LEFT JOIN t1 t2 ON (t1.a = t2.a AND t2.a = 2)
ORDER BY c;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 3 Using temporary; Using filesort
1 SIMPLE t2 const PRIMARY PRIMARY 4 const 1 Using where
SELECT t2.b as c FROM
t1 LEFT JOIN t1 t2 ON (t1.a = t2.a AND t2.a = 2)
ORDER BY c;
c
NULL
NULL
2
explain SELECT t1.b as a, t2.b as c FROM
t1 JOIN t1 t2 ON (t1.a = t2.a AND t2.a = 2)
ORDER BY c;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 const PRIMARY PRIMARY 4 const 1 NULL
1 SIMPLE t2 const PRIMARY PRIMARY 4 const 1 NULL
CREATE TABLE t2 LIKE t1;
INSERT INTO t2 SELECT * from t1;
CREATE TABLE t3 LIKE t1;
INSERT INTO t3 SELECT * from t1;
CREATE TABLE t4 LIKE t1;
INSERT INTO t4 SELECT * from t1;
INSERT INTO t1 values (0,0),(4,4);
SELECT t2.b FROM t1 LEFT JOIN (t2, t3 LEFT JOIN t4 ON t3.a=t4.a)
ON (t1.a=t2.a AND t1.b=t3.b) order by t2.b;
b
NULL
NULL
1
2
3
DROP TABLE t1,t2,t3,t4;
create table t1 (a int, b int, c int);
insert into t1 values (1,2,3), (9,8,3), (19,4,3), (1,4,9);
select a,(sum(b)/sum(c)) as ratio from t1 group by a order by sum(b)/sum(c) asc;
a ratio
1 0.5000
19 1.3333
9 2.6667
drop table t1;
CREATE TABLE t1 (a INT UNSIGNED NOT NULL, b TIME);
INSERT INTO t1 (a) VALUES (100000), (0), (100), (1000000),(10000), (1000), (10);
UPDATE t1 SET b = SEC_TO_TIME(a);
SELECT a, b FROM t1 ORDER BY b DESC;
a b
1000000 277:46:40
100000 27:46:40
10000 02:46:40
1000 00:16:40
100 00:01:40
10 00:00:10
0 00:00:00
SELECT a, b FROM t1 ORDER BY SEC_TO_TIME(a) DESC;
a b
1000000 277:46:40
100000 27:46:40
10000 02:46:40
1000 00:16:40
100 00:01:40
10 00:00:10
0 00:00:00
DROP TABLE t1;
CREATE TABLE t1 (a INT, b INT, PRIMARY KEY (a), UNIQUE KEY b (b));
INSERT INTO t1 VALUES (1,1),(2,2);
CREATE TABLE t2 (a INT, b INT, KEY a (a,b));
INSERT INTO t2 VALUES (1,1),(1,2),(2,1),(2,2);
EXPLAIN SELECT 1 FROM t1,t2 WHERE t1.b=2 AND t1.a=t2.a ORDER BY t2.b;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 const PRIMARY,b b 5 const 1 NULL
1 SIMPLE t2 ref a a 5 const 2 Using where; Using index
DROP TABLE t1,t2;
CREATE TABLE t1(
id int auto_increment PRIMARY KEY, c2 int, c3 int, INDEX k2(c2), INDEX k3(c3));
INSERT INTO t1 (c2,c3) VALUES
(31,34),(35,38),(34,31),(32,35),(31,39),
(11,14),(15,18),(14,11),(12,15),(11,19);
INSERT INTO t1 (c2,c3) SELECT c2,c3 FROM t1;
INSERT INTO t1 (c2,c3) SELECT c2,c3 FROM t1;
INSERT INTO t1 (c2,c3) SELECT c2,c3 FROM t1;
INSERT INTO t1 (c2,c3) SELECT c2,c3 FROM t1;
INSERT INTO t1 (c2,c3) SELECT c2,c3 FROM t1;
INSERT INTO t1 (c2,c3) SELECT c2,c3 FROM t1;
INSERT INTO t1 (c2,c3) SELECT c2,c3 FROM t1;
INSERT INTO t1 (c2,c3) SELECT c2,c3 FROM t1;
INSERT INTO t1 (c2,c3) SELECT c2,c3 FROM t1;
INSERT INTO t1 (c2,c3) SELECT c2,c3 FROM t1;
INSERT INTO t1 (c2,c3) SELECT c2,c3 FROM t1;
INSERT INTO t1 (c2,c3) SELECT c2,c3 FROM t1;
UPDATE t1 SET c2=20 WHERE id%100 = 0;
SELECT COUNT(*) FROM t1;
COUNT(*)
40960
CREATE TABLE t2 LIKE t1;
INSERT INTO t2 SELECT * FROM t1 ORDER BY id;
EXPLAIN SELECT id,c3 FROM t2 WHERE c2=11 ORDER BY c3 LIMIT 20;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 index k2 k3 5 NULL 111 Using where
EXPLAIN SELECT id,c3 FROM t2 WHERE c2=11 ORDER BY c3 LIMIT 4000;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ref k2 k2 5 const 7341 Using where; Using filesort
EXPLAIN SELECT id,c3 FROM t2 WHERE c2 BETWEEN 10 AND 12 ORDER BY c3 LIMIT 20;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 index k2 k3 5 NULL 73 Using where
EXPLAIN SELECT id,c3 FROM t2 WHERE c2 BETWEEN 20 AND 30 ORDER BY c3 LIMIT 4000;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range k2 k2 5 NULL 386 Using index condition; Using MRR; Using filesort
SELECT id,c3 FROM t2 WHERE c2=11 ORDER BY c3 LIMIT 20;
id c3
6 14
16 14
26 14
36 14
46 14
56 14
66 14
76 14
86 14
96 14
106 14
116 14
126 14
136 14
146 14
156 14
166 14
176 14
186 14
196 14
DROP TABLE t1,t2;
CREATE TABLE t1 (
a INT,
b INT,
PRIMARY KEY (a),
KEY ab(a, b)
);
INSERT INTO t1 VALUES (1,1),(2,2),(3,3),(4,4);
INSERT INTO t1 SELECT a + 4, b + 4 FROM t1;
INSERT INTO t1 SELECT a + 8, b + 8 FROM t1;
INSERT INTO t1 SELECT a +16, b +16 FROM t1;
INSERT INTO t1 SELECT a +32, b +32 FROM t1;
INSERT INTO t1 SELECT a +64, b +64 FROM t1;
EXPLAIN SELECT a FROM t1 IGNORE INDEX FOR GROUP BY (a, ab) GROUP BY a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range PRIMARY,ab ab 4 NULL 10 Using index for group-by
SELECT a FROM t1 IGNORE INDEX FOR GROUP BY (a, ab) GROUP BY a;
a
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
SELECT @tmp_tables_after = @tmp_tables_before ;
@tmp_tables_after = @tmp_tables_before
1
EXPLAIN SELECT a FROM t1 IGNORE INDEX FOR ORDER BY (a, ab) ORDER BY a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL PRIMARY 4 NULL 128 Using index
SELECT a FROM t1 IGNORE INDEX FOR ORDER BY (a, ab) ORDER BY a;
a
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
SELECT @tmp_tables_after = @tmp_tables_before;
@tmp_tables_after = @tmp_tables_before
1
DROP TABLE t1;
#
# Bug#31590: Wrong error message on sort buffer being too small.
#
create table t1(a int, b tinytext);
insert into t1 values (1,2),(3,2);
set session sort_buffer_size= 30000;
Warnings:
Warning 1292 Truncated incorrect sort_buffer_size value: '30000'
set session max_sort_length= 2180;
CALL mtr.add_suppression("Out of sort memory");
select * from t1 order by b;
ERROR HY001: Out of sort memory, consider increasing server sort buffer size
drop table t1;
call mtr.add_suppression("Out of sort memory; increase server sort buffer size");
#
# Bug #39844: Query Crash Mysql Server 5.0.67
#
CREATE TABLE t1 (a INT PRIMARY KEY);
CREATE TABLE t2 (a INT PRIMARY KEY, b INT);
CREATE TABLE t3 (c INT);
INSERT INTO t1 (a) VALUES (1), (2);
INSERT INTO t2 (a,b) VALUES (1,2), (2,3);
INSERT INTO t3 (c) VALUES (1), (2);
SELECT
(SELECT t1.a FROM t1, t2 WHERE t1.a = t2.b AND t2.a = t3.c ORDER BY t1.a)
FROM t3;
(SELECT t1.a FROM t1, t2 WHERE t1.a = t2.b AND t2.a = t3.c ORDER BY t1.a)
2
NULL
DROP TABLE t1, t2, t3;
#
# Bug #42760: Select doesn't return desired results when we have null
# values
#
CREATE TABLE t1 (
a INT,
c INT,
UNIQUE KEY a_c (a,c),
KEY (a));
INSERT INTO t1 VALUES (1, 10), (2, NULL);
# Must use ref-or-null on the a_c index
EXPLAIN
SELECT 1 AS col FROM t1 WHERE a=2 AND (c=10 OR c IS NULL) ORDER BY c;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref a_c,a a 5 const 1 Using where; Using filesort
# Must return 1 row
SELECT 1 AS col FROM t1 WHERE a=2 AND (c=10 OR c IS NULL) ORDER BY c;
col
1
# Must use ref-or-null on the a_c index
EXPLAIN
SELECT 1 AS col FROM t1 WHERE a=2 AND (c=10 OR c IS NULL) ORDER BY c DESC;
id select_type table type possible_keys key key_len ref rows Extra
x x x ref a_c,a x x x x x
# Must return 1 row
SELECT 1 AS col FROM t1 WHERE a=2 AND (c=10 OR c IS NULL) ORDER BY c DESC;
col
1
DROP TABLE t1;
End of 5.0 tests
CREATE TABLE t2 (a varchar(32), b int(11), c float, d double,
UNIQUE KEY a (a,b,c), KEY b (b), KEY c (c));
CREATE TABLE t1 (a varchar(32), b char(3), UNIQUE KEY a (a,b), KEY b (b));
CREATE TABLE t3 (a varchar(32), b char(3), UNIQUE KEY a (a,b));
INSERT INTO t3 SELECT * FROM t1;
EXPLAIN
SELECT d FROM t1, t2
WHERE t2.b=14 AND t2.a=t1.a AND 5.1<t2.c AND t1.b='DE'
ORDER BY t2.c LIMIT 1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref a,b b 4 const 4 Using index condition; Using where; Using temporary; Using filesort
1 SIMPLE t2 ref a,b,c a 40 test.t1.a,const 11 Using index condition
SELECT d FROM t1, t2
WHERE t2.b=14 AND t2.a=t1.a AND 5.1<t2.c AND t1.b='DE'
ORDER BY t2.c LIMIT 1;
d
52.5
EXPLAIN
SELECT d FROM t3 AS t1, t2 AS t2
WHERE t2.b=14 AND t2.a=t1.a AND 5.1<t2.c AND t1.b='DE'
ORDER BY t2.c LIMIT 1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range a,b,c c 5 NULL 420 Using where
1 SIMPLE t1 ref a a 39 test.t2.a,const 10 Using where; Using index
SELECT d FROM t3 AS t1, t2 AS t2
WHERE t2.b=14 AND t2.a=t1.a AND 5.1<t2.c AND t1.b='DE'
ORDER BY t2.c LIMIT 1;
d
52.5
DROP TABLE t1,t2,t3;
#
# WL#1393 - Optimizing filesort with small limit
#
CREATE TABLE t1(f0 int auto_increment primary key, f1 int, f2 varchar(200));
INSERT INTO t1(f1, f2) VALUES
(0,"0"),(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"),
(21,"21"),(22,"22"),(23,"23"),(24,"24"),(25,"25"),
(26,"26"),(27,"27"),(28,"28"),(29,"29"),(30,"30"),
(31,"31"),(32,"32"),(33,"33"),(34,"34"),(35,"35"),
(36,"36"),(37,"37"),(38,"38"),(39,"39"),(40,"40"),
(41,"41"),(42,"42"),(43,"43"),(44,"44"),(45,"45"),
(46,"46"),(47,"47"),(48,"48"),(49,"49"),(50,"50"),
(51,"51"),(52,"52"),(53,"53"),(54,"54"),(55,"55"),
(56,"56"),(57,"57"),(58,"58"),(59,"59"),(60,"60"),
(61,"61"),(62,"62"),(63,"63"),(64,"64"),(65,"65"),
(66,"66"),(67,"67"),(68,"68"),(69,"69"),(70,"70"),
(71,"71"),(72,"72"),(73,"73"),(74,"74"),(75,"75"),
(76,"76"),(77,"77"),(78,"78"),(79,"79"),(80,"80"),
(81,"81"),(82,"82"),(83,"83"),(84,"84"),(85,"85"),
(86,"86"),(87,"87"),(88,"88"),(89,"89"),(90,"90"),
(91,"91"),(92,"92"),(93,"93"),(94,"94"),(95,"95"),
(96,"96"),(97,"97"),(98,"98"),(99,"99");
SELECT * FROM t1 ORDER BY f1 ASC, f0 LIMIT 100;
f0 f1 f2
1 0 0
2 1 1
3 2 2
4 3 3
5 4 4
6 5 5
7 6 6
8 7 7
9 8 8
10 9 9
11 10 10
12 11 11
13 12 12
14 13 13
15 14 14
16 15 15
17 16 16
18 17 17
19 18 18
20 19 19
21 20 20
22 21 21
23 22 22
24 23 23
25 24 24
26 25 25
27 26 26
28 27 27
29 28 28
30 29 29
31 30 30
32 31 31
33 32 32
34 33 33
35 34 34
36 35 35
37 36 36
38 37 37
39 38 38
40 39 39
41 40 40
42 41 41
43 42 42
44 43 43
45 44 44
46 45 45
47 46 46
48 47 47
49 48 48
50 49 49
51 50 50
52 51 51
53 52 52
54 53 53
55 54 54
56 55 55
57 56 56
58 57 57
59 58 58
60 59 59
61 60 60
62 61 61
63 62 62
64 63 63
65 64 64
66 65 65
67 66 66
68 67 67
69 68 68
70 69 69
71 70 70
72 71 71
73 72 72
74 73 73
75 74 74
76 75 75
77 76 76
78 77 77
79 78 78
80 79 79
81 80 80
82 81 81
83 82 82
84 83 83
85 84 84
86 85 85
87 86 86
88 87 87
89 88 88
90 89 89
91 90 90
92 91 91
93 92 92
94 93 93
95 94 94
96 95 95
97 96 96
98 97 97
99 98 98
100 99 99
SELECT * FROM t1 ORDER BY f1 ASC, f0 LIMIT 30;
f0 f1 f2
1 0 0
2 1 1
3 2 2
4 3 3
5 4 4
6 5 5
7 6 6
8 7 7
9 8 8
10 9 9
11 10 10
12 11 11
13 12 12
14 13 13
15 14 14
16 15 15
17 16 16
18 17 17
19 18 18
20 19 19
21 20 20
22 21 21
23 22 22
24 23 23
25 24 24
26 25 25
27 26 26
28 27 27
29 28 28
30 29 29
SELECT * FROM t1 ORDER BY f1 ASC, f0 LIMIT 0;
f0 f1 f2
SELECT * FROM t1 ORDER BY f2 DESC, f0 LIMIT 30;
f0 f1 f2
100 99 99
99 98 98
98 97 97
97 96 96
96 95 95
95 94 94
94 93 93
93 92 92
92 91 91
91 90 90
10 9 9
90 89 89
89 88 88
88 87 87
87 86 86
86 85 85
85 84 84
84 83 83
83 82 82
82 81 81
81 80 80
9 8 8
80 79 79
79 78 78
78 77 77
77 76 76
76 75 75
75 74 74
74 73 73
73 72 72
SELECT * FROM t1 ORDER BY f2 DESC, f0 LIMIT 0;
f0 f1 f2
SELECT * FROM t1 WHERE f1>10 ORDER BY f2, f0 LIMIT 20;
f0 f1 f2
12 11 11
13 12 12
14 13 13
15 14 14
16 15 15
17 16 16
18 17 17
19 18 18
20 19 19
21 20 20
22 21 21
23 22 22
24 23 23
25 24 24
26 25 25
27 26 26
28 27 27
29 28 28
30 29 29
31 30 30
SELECT * FROM t1 WHERE f1>10 ORDER BY f2, f0 LIMIT 0;
f0 f1 f2
SELECT * FROM t1 WHERE f1>10 ORDER BY f2, f0 LIMIT 10 OFFSET 10;
f0 f1 f2
22 21 21
23 22 22
24 23 23
25 24 24
26 25 25
27 26 26
28 27 27
29 28 28
30 29 29
31 30 30
SELECT * FROM t1 WHERE f1>10 ORDER BY f2, f0 LIMIT 0 OFFSET 10;
f0 f1 f2
set sort_buffer_size= 32768;
CREATE TEMPORARY TABLE tmp (f1 int, f2 varchar(20));
INSERT INTO tmp SELECT f1, f2 FROM t1;
INSERT INTO t1(f1, f2) SELECT * FROM tmp;
INSERT INTO tmp SELECT f1, f2 FROM t1;
INSERT INTO t1(f1, f2) SELECT * FROM tmp;
SELECT * FROM t1 ORDER BY f1 ASC, f0 LIMIT 30;
f0 f1 f2
1 0 0
101 0 0
201 0 0
301 0 0
401 0 0
2 1 1
102 1 1
202 1 1
302 1 1
402 1 1
3 2 2
103 2 2
203 2 2
303 2 2
403 2 2
4 3 3
104 3 3
204 3 3
304 3 3
404 3 3
5 4 4
105 4 4
205 4 4
305 4 4
405 4 4
6 5 5
106 5 5
206 5 5
306 5 5
406 5 5
SELECT * FROM t1 ORDER BY f1 ASC, f0 LIMIT 0;
f0 f1 f2
SELECT * FROM t1 ORDER BY f2 DESC, f0 LIMIT 30;
f0 f1 f2
100 99 99
200 99 99
300 99 99
400 99 99
500 99 99
99 98 98
199 98 98
299 98 98
399 98 98
499 98 98
98 97 97
198 97 97
298 97 97
398 97 97
498 97 97
97 96 96
197 96 96
297 96 96
397 96 96
497 96 96
96 95 95
196 95 95
296 95 95
396 95 95
496 95 95
95 94 94
195 94 94
295 94 94
395 94 94
495 94 94
SELECT * FROM t1 ORDER BY f2 DESC, f0 LIMIT 0;
f0 f1 f2
SELECT * FROM t1 WHERE f1>10 ORDER BY f2, f0 LIMIT 20;
f0 f1 f2
12 11 11
112 11 11
212 11 11
312 11 11
412 11 11
13 12 12
113 12 12
213 12 12
313 12 12
413 12 12
14 13 13
114 13 13
214 13 13
314 13 13
414 13 13
15 14 14
115 14 14
215 14 14
315 14 14
415 14 14
SELECT * FROM t1 WHERE f1>10 ORDER BY f2, f0 LIMIT 0;
f0 f1 f2
SELECT * FROM t1 WHERE f1>10 ORDER BY f2, f0 LIMIT 10 OFFSET 10;
f0 f1 f2
14 13 13
114 13 13
214 13 13
314 13 13
414 13 13
15 14 14
115 14 14
215 14 14
315 14 14
415 14 14
SELECT * FROM t1 WHERE f1>10 ORDER BY f2, f0 LIMIT 0 OFFSET 10;
f0 f1 f2
set sort_buffer_size= 32768;
SELECT SQL_CALC_FOUND_ROWS * FROM t1
ORDER BY f1, f0 LIMIT 30;
f0 f1 f2
1 0 0
101 0 0
201 0 0
301 0 0
401 0 0
2 1 1
102 1 1
202 1 1
302 1 1
402 1 1
3 2 2
103 2 2
203 2 2
303 2 2
403 2 2
4 3 3
104 3 3
204 3 3
304 3 3
404 3 3
5 4 4
105 4 4
205 4 4
305 4 4
405 4 4
6 5 5
106 5 5
206 5 5
306 5 5
406 5 5
SELECT FOUND_ROWS();
FOUND_ROWS()
500
SELECT SQL_CALC_FOUND_ROWS * FROM t1
ORDER BY f1, f0 LIMIT 0;
f0 f1 f2
SELECT FOUND_ROWS();
FOUND_ROWS()
500
SELECT SQL_CALC_FOUND_ROWS * FROM t1 WHERE f1>10
ORDER BY f2, f0 LIMIT 20;
f0 f1 f2
12 11 11
112 11 11
212 11 11
312 11 11
412 11 11
13 12 12
113 12 12
213 12 12
313 12 12
413 12 12
14 13 13
114 13 13
214 13 13
314 13 13
414 13 13
15 14 14
115 14 14
215 14 14
315 14 14
415 14 14
SELECT FOUND_ROWS();
FOUND_ROWS()
445
SELECT SQL_CALC_FOUND_ROWS * FROM t1 WHERE f1>10
ORDER BY f2, f0 LIMIT 0;
f0 f1 f2
SELECT FOUND_ROWS();
FOUND_ROWS()
445
SELECT SQL_CALC_FOUND_ROWS * FROM t1 WHERE f1>10
ORDER BY f2, f0 LIMIT 10 OFFSET 10;
f0 f1 f2
14 13 13
114 13 13
214 13 13
314 13 13
414 13 13
15 14 14
115 14 14
215 14 14
315 14 14
415 14 14
SELECT FOUND_ROWS();
FOUND_ROWS()
445
SELECT SQL_CALC_FOUND_ROWS * FROM t1 WHERE f1>10
ORDER BY f2, f0 LIMIT 0 OFFSET 10;
f0 f1 f2
SELECT FOUND_ROWS();
FOUND_ROWS()
445
set sort_buffer_size= 327680;
SELECT * FROM t1 JOIN tmp on t1.f2=tmp.f2
ORDER BY tmp.f1, f0 LIMIT 30;
f0 f1 f2 f1 f2
1 0 0 0 0
1 0 0 0 0
1 0 0 0 0
101 0 0 0 0
101 0 0 0 0
101 0 0 0 0
201 0 0 0 0
201 0 0 0 0
201 0 0 0 0
301 0 0 0 0
301 0 0 0 0
301 0 0 0 0
401 0 0 0 0
401 0 0 0 0
401 0 0 0 0
2 1 1 1 1
2 1 1 1 1
2 1 1 1 1
102 1 1 1 1
102 1 1 1 1
102 1 1 1 1
202 1 1 1 1
202 1 1 1 1
202 1 1 1 1
302 1 1 1 1
302 1 1 1 1
302 1 1 1 1
402 1 1 1 1
402 1 1 1 1
402 1 1 1 1
SELECT * FROM t1 JOIN tmp on t1.f2=tmp.f2
ORDER BY tmp.f1, f0 LIMIT 30 OFFSET 30;
f0 f1 f2 f1 f2
3 2 2 2 2
3 2 2 2 2
3 2 2 2 2
103 2 2 2 2
103 2 2 2 2
103 2 2 2 2
203 2 2 2 2
203 2 2 2 2
203 2 2 2 2
303 2 2 2 2
303 2 2 2 2
303 2 2 2 2
403 2 2 2 2
403 2 2 2 2
403 2 2 2 2
4 3 3 3 3
4 3 3 3 3
4 3 3 3 3
104 3 3 3 3
104 3 3 3 3
104 3 3 3 3
204 3 3 3 3
204 3 3 3 3
204 3 3 3 3
304 3 3 3 3
304 3 3 3 3
304 3 3 3 3
404 3 3 3 3
404 3 3 3 3
404 3 3 3 3
SELECT SQL_CALC_FOUND_ROWS * FROM t1 JOIN tmp on t1.f2=tmp.f2
ORDER BY tmp.f1, f0 LIMIT 30 OFFSET 30;
f0 f1 f2 f1 f2
3 2 2 2 2
3 2 2 2 2
3 2 2 2 2
103 2 2 2 2
103 2 2 2 2
103 2 2 2 2
203 2 2 2 2
203 2 2 2 2
203 2 2 2 2
303 2 2 2 2
303 2 2 2 2
303 2 2 2 2
403 2 2 2 2
403 2 2 2 2
403 2 2 2 2
4 3 3 3 3
4 3 3 3 3
4 3 3 3 3
104 3 3 3 3
104 3 3 3 3
104 3 3 3 3
204 3 3 3 3
204 3 3 3 3
204 3 3 3 3
304 3 3 3 3
304 3 3 3 3
304 3 3 3 3
404 3 3 3 3
404 3 3 3 3
404 3 3 3 3
SELECT FOUND_ROWS();
FOUND_ROWS()
1500
SELECT SQL_CALC_FOUND_ROWS * FROM t1 JOIN tmp on t1.f2=tmp.f2
WHERE t1.f2>20
ORDER BY tmp.f1, f0 LIMIT 30 OFFSET 30;
f0 f1 f2 f1 f2
24 23 23 23 23
24 23 23 23 23
24 23 23 23 23
124 23 23 23 23
124 23 23 23 23
124 23 23 23 23
224 23 23 23 23
224 23 23 23 23
224 23 23 23 23
324 23 23 23 23
324 23 23 23 23
324 23 23 23 23
424 23 23 23 23
424 23 23 23 23
424 23 23 23 23
25 24 24 24 24
25 24 24 24 24
25 24 24 24 24
125 24 24 24 24
125 24 24 24 24
125 24 24 24 24
225 24 24 24 24
225 24 24 24 24
225 24 24 24 24
325 24 24 24 24
325 24 24 24 24
325 24 24 24 24
425 24 24 24 24
425 24 24 24 24
425 24 24 24 24
SELECT FOUND_ROWS();
FOUND_ROWS()
1185
CREATE VIEW v1 as SELECT * FROM t1 ORDER BY f1, f0 LIMIT 30;
SELECT * FROM v1;
f0 f1 f2
1 0 0
101 0 0
201 0 0
301 0 0
401 0 0
2 1 1
102 1 1
202 1 1
302 1 1
402 1 1
3 2 2
103 2 2
203 2 2
303 2 2
403 2 2
4 3 3
104 3 3
204 3 3
304 3 3
404 3 3
5 4 4
105 4 4
205 4 4
305 4 4
405 4 4
6 5 5
106 5 5
206 5 5
306 5 5
406 5 5
drop view v1;
CREATE VIEW v1 as SELECT * FROM t1 ORDER BY f1, f0 LIMIT 100;
SELECT * FROM v1 ORDER BY f2, f0 LIMIT 30;
f0 f1 f2
1 0 0
101 0 0
201 0 0
301 0 0
401 0 0
2 1 1
102 1 1
202 1 1
302 1 1
402 1 1
11 10 10
111 10 10
211 10 10
311 10 10
411 10 10
12 11 11
112 11 11
212 11 11
312 11 11
412 11 11
13 12 12
113 12 12
213 12 12
313 12 12
413 12 12
14 13 13
114 13 13
214 13 13
314 13 13
414 13 13
CREATE VIEW v2 as SELECT * FROM t1 ORDER BY f2, f0 LIMIT 100;
SELECT * FROM v1 JOIN v2 on v1.f1=v2.f1 ORDER BY v1.f2,v1.f0,v2.f0
LIMIT 30;
f0 f1 f2 f0 f1 f2
1 0 0 1 0 0
1 0 0 101 0 0
1 0 0 201 0 0
1 0 0 301 0 0
1 0 0 401 0 0
101 0 0 1 0 0
101 0 0 101 0 0
101 0 0 201 0 0
101 0 0 301 0 0
101 0 0 401 0 0
201 0 0 1 0 0
201 0 0 101 0 0
201 0 0 201 0 0
201 0 0 301 0 0
201 0 0 401 0 0
301 0 0 1 0 0
301 0 0 101 0 0
301 0 0 201 0 0
301 0 0 301 0 0
301 0 0 401 0 0
401 0 0 1 0 0
401 0 0 101 0 0
401 0 0 201 0 0
401 0 0 301 0 0
401 0 0 401 0 0
2 1 1 2 1 1
2 1 1 102 1 1
2 1 1 202 1 1
2 1 1 302 1 1
2 1 1 402 1 1
SELECT floor(f1/10) f3, count(f2) FROM t1
GROUP BY 1 ORDER BY 2,1 LIMIT 5;
f3 count(f2)
0 50
1 50
2 50
3 50
4 50
SELECT floor(f1/10) f3, count(f2) FROM t1
GROUP BY 1 ORDER BY 2,1 LIMIT 0;
f3 count(f2)
CREATE PROCEDURE wl1393_sp_test()
BEGIN
SELECT * FROM t1 WHERE f1>10 ORDER BY f2, f0 LIMIT 30;
SELECT * FROM t1 WHERE f1>10 ORDER BY f2, f0 LIMIT 15 OFFSET 15;
SELECT SQL_CALC_FOUND_ROWS * FROM t1 WHERE f1>10
ORDER BY f2, f0 LIMIT 15 OFFSET 15;
SELECT FOUND_ROWS();
SELECT * FROM v1 ORDER BY f2, f0 LIMIT 30;
END|
CALL wl1393_sp_test()|
f0 f1 f2
12 11 11
112 11 11
212 11 11
312 11 11
412 11 11
13 12 12
113 12 12
213 12 12
313 12 12
413 12 12
14 13 13
114 13 13
214 13 13
314 13 13
414 13 13
15 14 14
115 14 14
215 14 14
315 14 14
415 14 14
16 15 15
116 15 15
216 15 15
316 15 15
416 15 15
17 16 16
117 16 16
217 16 16
317 16 16
417 16 16
f0 f1 f2
15 14 14
115 14 14
215 14 14
315 14 14
415 14 14
16 15 15
116 15 15
216 15 15
316 15 15
416 15 15
17 16 16
117 16 16
217 16 16
317 16 16
417 16 16
f0 f1 f2
15 14 14
115 14 14
215 14 14
315 14 14
415 14 14
16 15 15
116 15 15
216 15 15
316 15 15
416 15 15
17 16 16
117 16 16
217 16 16
317 16 16
417 16 16
FOUND_ROWS()
445
f0 f1 f2
1 0 0
101 0 0
201 0 0
301 0 0
401 0 0
2 1 1
102 1 1
202 1 1
302 1 1
402 1 1
11 10 10
111 10 10
211 10 10
311 10 10
411 10 10
12 11 11
112 11 11
212 11 11
312 11 11
412 11 11
13 12 12
113 12 12
213 12 12
313 12 12
413 12 12
14 13 13
114 13 13
214 13 13
314 13 13
414 13 13
DROP PROCEDURE wl1393_sp_test|
SELECT d1.f1, d1.f2 FROM t1
LEFT JOIN (SELECT * FROM t1 ORDER BY f1 LIMIT 30) d1 on t1.f1=d1.f1
ORDER BY d1.f2 DESC LIMIT 30;
f1 f2
5 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
5 5
4 4
4 4
4 4
4 4
4 4
SELECT * FROM t1 WHERE f1 = (SELECT f1 FROM t1 ORDER BY 1 LIMIT 1);
f0 f1 f2
1 0 0
101 0 0
201 0 0
301 0 0
401 0 0
SELECT * FROM t1 WHERE f1 = (SELECT f1 FROM t1 ORDER BY 1 LIMIT 2);
ERROR 21000: Subquery returns more than 1 row
DROP TABLE t1, tmp;
DROP VIEW v1, v2;
# end of WL#1393 - Optimizing filesort with small limit
#
# Bug #58761
# Crash in Field::is_null in field.h on subquery in WHERE clause
#
CREATE TABLE t1 (
pk INT NOT NULL AUTO_INCREMENT,
col_int_key INT DEFAULT NULL,
col_varchar_key VARCHAR(1) DEFAULT NULL,
PRIMARY KEY (pk),
KEY col_varchar_key (col_varchar_key,col_int_key)
);
INSERT INTO t1 VALUES (27,7,'x');
INSERT INTO t1 VALUES (28,6,'m');
INSERT INTO t1 VALUES (29,4,'c');
CREATE TABLE where_subselect
SELECT DISTINCT `pk` AS field1 , `pk` AS field2
FROM t1 AS alias1
WHERE alias1 . `col_int_key` > 229
OR alias1 . `col_varchar_key` IS NOT NULL
GROUP BY field1, field2
;
SELECT *
FROM where_subselect
WHERE (field1, field2) IN (
SELECT DISTINCT `pk` AS field1 , `pk` AS field2
FROM t1 AS alias1
WHERE alias1 . `col_int_key` > 229
OR alias1 . `col_varchar_key` IS NOT NULL
GROUP BY field1, field2
);
field1 field2
27 27
28 28
29 29
DROP TABLE t1;
DROP TABLE where_subselect;
# End of Bug #58761
CREATE TABLE t1 (
id1 INT NULL,
id2 INT NOT NULL,
junk INT NOT NULL,
PRIMARY KEY (id1, id2, junk),
INDEX id2_j_id1 (id2, junk, id1)
);
INSERT INTO t1 VALUES (1, 1, 1), (2, 1, 2), (3, 1, 3), (4, 1, 4);
INSERT INTO t1 VALUES (5, 2, 1), (6, 2, 2), (7, 2, 3), (8, 2, 4);
INSERT INTO t1 VALUES (9, 3, 1), (10, 3, 2), (11, 3, 3), (12, 3, 4);
INSERT INTO t1 VALUES (13, 4, 1), (14, 4, 2), (15, 4, 3), (16, 4, 4);
INSERT INTO t1 VALUES (17, 5, 1), (18, 5, 2), (19, 5, 3), (20, 5, 4);
INSERT INTO t1 VALUES (21, 6, 1), (22, 6, 2), (23, 6, 3), (24, 6, 4);
INSERT INTO t1 VALUES (25, 7, 1), (26, 7, 2), (27, 7, 3), (28, 7, 4);
INSERT INTO t1 VALUES (29, 8, 1), (30, 8, 2), (31, 8, 3), (32, 8, 4);
INSERT INTO t1 VALUES (33, 9, 1), (34, 9, 2), (35, 9, 3), (36, 9, 4);
EXPLAIN SELECT id1 FROM t1 WHERE id2 = 4 ORDER BY id1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref id2_j_id1 id2_j_id1 4 const 4 Using where; Using index; Using filesort
SELECT id1 FROM t1 WHERE id2 = 4 ORDER BY id1;
id1
13
14
15
16
DROP TABLE t1;
CREATE TABLE t1 (
a INT,
b INT NOT NULL,
c char(100),
KEY (b, c),
KEY (b, a, c)
)
DEFAULT CHARSET = utf8;
INSERT INTO t1 VALUES
(1, 1, 1),
(2, 2, 2),
(3, 3, 3),
(4, 4, 4),
(5, 5, 5),
(6, 6, 6),
(7, 7, 7),
(8, 8, 8),
(9, 9, 9);
INSERT INTO t1 SELECT a + 10, b, c FROM t1;
INSERT INTO t1 SELECT a + 20, b, c FROM t1;
INSERT INTO t1 SELECT a + 40, b, c FROM t1;
INSERT INTO t1 SELECT a + 80, b, c FROM t1;
INSERT INTO t1 SELECT a + 160, b, c FROM t1;
INSERT INTO t1 SELECT a + 320, b, c FROM t1;
INSERT INTO t1 SELECT a + 640, b, c FROM t1;
INSERT INTO t1 SELECT a + 1280, b, c FROM t1 LIMIT 80;
EXPLAIN
SELECT a FROM t1 WHERE b = 1 ORDER BY c DESC LIMIT 9;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range b,b_2 b 4 NULL 226 Using where
SELECT a FROM t1 WHERE b = 1 ORDER BY c DESC LIMIT 9;
a
2071
2061
2051
2041
2031
2021
2011
2001
1991
EXPLAIN
SELECT DISTINCT a FROM t1 WHERE b = 1 ORDER BY c DESC LIMIT 0, 9;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range b,b_2 b 4 NULL 226 Using where; Using temporary
SELECT DISTINCT a FROM t1 WHERE b = 1 ORDER BY c DESC LIMIT 0, 9;
a
2071
2061
2051
2041
2031
2021
2011
2001
1991
DROP TABLE t1;
#
# Bug #43029: FORCE INDEX FOR ORDER BY is ignored when join buffering
# is used
#
CREATE TABLE t1 (a INT, b INT, KEY (a));
INSERT INTO t1 VALUES (0, NULL), (1, NULL), (2, NULL), (3, NULL);
INSERT INTO t1 SELECT a+4, b FROM t1;
INSERT INTO t1 SELECT a+8, b FROM t1;
CREATE TABLE t2 (a INT, b INT);
INSERT INTO t2 VALUES (0,NULL), (1,NULL), (2,NULL), (3,NULL), (4,NULL);
INSERT INTO t2 SELECT a+4, b FROM t2;
# shouldn't have "using filesort"
EXPLAIN
SELECT * FROM t1 FORCE INDEX FOR ORDER BY (a), t2 WHERE t1.a < 2 ORDER BY t1.a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 2 Using index condition
1 SIMPLE t2 ALL NULL NULL NULL NULL 10 NULL
# should have "using filesort"
EXPLAIN
SELECT * FROM t1 USE INDEX FOR ORDER BY (a), t2 WHERE t1.a < 2 ORDER BY t1.a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 2 Using index condition; Using MRR; Using temporary; Using filesort
1 SIMPLE t2 ALL NULL NULL NULL NULL 10 Using join buffer (Block Nested Loop)
# should have "using filesort"
EXPLAIN
SELECT * FROM t1 FORCE INDEX FOR JOIN (a), t2 WHERE t1.a < 2 ORDER BY t1.a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range a a 5 NULL 2 Using index condition; Using MRR; Using temporary; Using filesort
1 SIMPLE t2 ALL NULL NULL NULL NULL 10 Using join buffer (Block Nested Loop)
DROP TABLE t1, t2;
#
# Bug #50394: Regression in EXPLAIN with index scan, LIMIT, GROUP BY and
# ORDER BY computed col
#
CREATE TABLE t1 ( a INT NOT NULL, b INT NOT NULL, KEY( a, b ) );
INSERT INTO t1 VALUES (1, 1), (2, 2), (3, 3), (4, 4), (5, 5);
INSERT INTO t1 SELECT a + 5, b + 5 FROM t1;
CREATE TABLE t2( a INT PRIMARY KEY, b INT );
INSERT INTO t2 VALUES (1, 1), (2, 2), (3, 3), (4, 4), (5, 5);
INSERT INTO t2 SELECT a + 5, b + 5 FROM t2;
EXPLAIN
SELECT count(*) AS c, t1.a
FROM t1 JOIN t2 ON t1.b = t2.a
WHERE t2.b = 1
GROUP BY t1.a
ORDER by c
LIMIT 2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index a a 8 NULL 10 Using index; Using temporary; Using filesort
1 SIMPLE t2 eq_ref PRIMARY PRIMARY 4 test.t1.b 1 Using where
DROP TABLE t1, t2;
#
# Bug #59110: Memory leak of QUICK_SELECT_I allocated memory
# and
# Bug #59308: Incorrect result for
SELECT DISTINCT <col>... ORDER BY <col> DESC
# Use Valgrind to detect #59110!
#
CREATE TABLE t1 (a INT,KEY (a));
INSERT INTO t1 VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9),(10);
EXPLAIN SELECT DISTINCT a,1 FROM t1 WHERE a <> 1 ORDER BY a DESC;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index a a 5 NULL 10 Using where; Using index
SELECT DISTINCT a,1 FROM t1 WHERE a <> 1 ORDER BY a DESC;
a 1
10 1
9 1
8 1
7 1
6 1
5 1
4 1
3 1
2 1
DROP TABLE t1;
#
# Bug#11765255 58201:
# VALGRIND/CRASH WHEN ORDERING BY MULTIPLE AGGREGATE FUNCTIONS
#
select 1 order by max(1) + min(1);
1
1
End of 5.1 tests
#
# Bug #38745: MySQL 5.1 optimizer uses filesort for ORDER BY
# when it should use index
#
CREATE TABLE t1 (i1 integer NOT NULL PRIMARY KEY);
CREATE TABLE t2 (i2 integer NOT NULL PRIMARY KEY);
CREATE TABLE t3 (i3 integer);
INSERT INTO t1 VALUES (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (12);
INSERT INTO t2 SELECT * FROM t1;
EXPLAIN EXTENDED
SELECT t1.*, t2.* FROM t1 JOIN t2 ON t1.i1 = t2.i2
LEFT JOIN t3 ON t2.i2 = t3.i3
ORDER BY t1.i1 LIMIT 5;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t3 system NULL NULL NULL NULL 0 0.00 const row not found
1 SIMPLE t1 index PRIMARY PRIMARY 4 NULL 5 240.00 Using index
1 SIMPLE t2 eq_ref PRIMARY PRIMARY 4 test.t1.i1 1 100.00 Using index
Warnings:
Note 1003 /* select#1 */ select `test`.`t1`.`i1` AS `i1`,`test`.`t2`.`i2` AS `i2` from `test`.`t1` join `test`.`t2` where (`test`.`t2`.`i2` = `test`.`t1`.`i1`) order by `test`.`t1`.`i1` limit 5
SELECT t1.*, t2.* FROM t1 JOIN t2 ON t1.i1 = t2.i2
LEFT JOIN t3 ON t2.i2 = t3.i3
ORDER BY t1.i1 LIMIT 5;
i1 i2
1 1
2 2
3 3
4 4
5 5
DROP TABLE t1, t2, t3;
#
# Bug #11885377 VOID JOIN_READ_KEY_UNLOCK_ROW(ST_JOIN_TABLE*): ASSERTION
# `TAB->REF.USE_COUNT'
#
CREATE TABLE t1(a INT PRIMARY KEY);
CREATE TABLE t2(b INT,c INT);
INSERT INTO t1 VALUES (1), (2);
INSERT INTO t2 VALUES (1,2), (2,3);
SELECT (SELECT 1 FROM t1 WHERE a=b AND c=1 ORDER BY a DESC) FROM t2;
(SELECT 1 FROM t1 WHERE a=b AND c=1 ORDER BY a DESC)
NULL
NULL
DROP TABLE t1, t2;
#
# Bug #13531865
# TEST_IF_SKIP_SORT_ORDER() INCORRECTLY SKIP FILESORT IF
# 'TYPE' IS REF_OR_NULL
#
#
CREATE TABLE t1 (
a INT,
c INT,
UNIQUE KEY a_c (a,c),
KEY (a)) engine=myisam;
INSERT INTO t1 VALUES (1,10), (2,NULL), (2,10);
ANALYZE TABLE t1;
Table Op Msg_type Msg_text
test.t1 analyze status OK
# Using 'KEY a_c' for order-by opt, would have required
# REF_OR_NULL access which never can be order_by skipped.
# -> Keep initial REF on 'KEY a' selected by cond. optimizer
EXPLAIN
SELECT c FROM t1 WHERE a=2 AND (c=10 OR c IS NULL);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref a_c,a a 5 const 1 Using where
EXPLAIN
SELECT c FROM t1 WHERE a=2 AND (c=10 OR c IS NULL) ORDER BY c;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref a_c,a a 5 const 1 Using where; Using filesort
SELECT c FROM t1 WHERE a=2 AND (c=10 OR c IS NULL) ORDER BY c;
c
NULL
10
EXPLAIN
SELECT c FROM t1 WHERE a=2 AND (c=10 OR c IS NULL) ORDER BY c DESC;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref a_c,a a 5 const 1 Using where; Using filesort
SELECT c FROM t1 WHERE a=2 AND (c=10 OR c IS NULL) ORDER BY c DESC;
c
10
NULL
DROP TABLE t1;
#
# Bug #13528826
# TEST_IF_CHEAPER_ORDERING(): CALCULATES INCORRECT 'SELECT_LIMIT'
#
#
CREATE TABLE t1(a int PRIMARY KEY, b int) ENGINE=myisam;
INSERT INTO t1 VALUES
(5, 10), (2, 70), (7, 80), (6, 20), (1, 50), (9, 40), (8, 30), (3, 60);
CREATE TABLE t2 (p int, a int, INDEX i_a(a)) ENGINE=myisam;
INSERT INTO t2 VALUES
(103, 7), (109, 3), (102, 3), (108, 1), (106, 3),
(107, 7), (105, 1), (101, 3), (100, 7), (110, 1);
# number of rows in t1 was incorrectly used as an
# implicit limit-clause if not explicit specified
EXPLAIN
SELECT t1.a FROM t1 LEFT JOIN t2 ON t1.a=t2.a ORDER BY t1.a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL PRIMARY 4 NULL 8 Using index
1 SIMPLE t2 ref i_a i_a 5 test.t1.a 2 Using index
# Query above used to be explained identical to this:
EXPLAIN
SELECT t1.a FROM t1 LEFT JOIN t2 ON t1.a=t2.a ORDER BY t1.a LIMIT 8;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL PRIMARY 4 NULL 4 Using index
1 SIMPLE t2 ref i_a i_a 5 test.t1.a 2 Using index
# A really high limit was required to give the correct explain
EXPLAIN
SELECT t1.a FROM t1 LEFT JOIN t2 ON t1.a=t2.a ORDER BY t1.a LIMIT 1000;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL PRIMARY 4 NULL 8 Using index
1 SIMPLE t2 ref i_a i_a 5 test.t1.a 2 Using index
DROP TABLE t1, t2;
#
# Bug #13949068 ASSERT TAB->REF.KEY == REF_KEY IN
# PLAN_CHANGE_WATCHDOG::~PLAN_CHANGE_WATCHDOG
#
CREATE TABLE t1 (a INT, b INT, KEY(b), KEY(b,a)) ENGINE=INNODB;
INSERT INTO t1 VALUES (0,0);
EXPLAIN SELECT DISTINCT a FROM t1 WHERE b=1 ORDER BY 1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref b,b_2 b_2 5 const 1 Using where
SELECT DISTINCT a FROM t1 WHERE b=1 ORDER BY 1;
a
DROP TABLE t1;
set optimizer_switch=default;