drop table if exists t1;
CREATE TABLE t1 (
event_date date DEFAULT '0000-00-00' NOT NULL,
type int(11) DEFAULT '0' NOT NULL,
event_id int(11) DEFAULT '0' NOT NULL,
PRIMARY KEY (event_date,type,event_id)
);
INSERT INTO t1 VALUES ('1999-07-10',100100,24), ('1999-07-11',100100,25),
('1999-07-13',100600,0), ('1999-07-13',100600,4), ('1999-07-13',100600,26),
('1999-07-14',100600,10), ('1999-07-15',100600,16), ('1999-07-15',100800,45),
('1999-07-15',101000,47), ('1999-07-16',100800,46), ('1999-07-20',100600,5),
('1999-07-20',100600,27), ('1999-07-21',100600,11), ('1999-07-22',100600,17),
('1999-07-23',100100,39), ('1999-07-24',100100,39), ('1999-07-24',100500,40),
('1999-07-25',100100,39), ('1999-07-27',100600,1), ('1999-07-27',100600,6),
('1999-07-27',100600,28), ('1999-07-28',100600,12), ('1999-07-29',100500,41),
('1999-07-29',100600,18), ('1999-07-30',100500,41), ('1999-07-31',100500,41),
('1999-08-01',100700,34), ('1999-08-03',100600,7), ('1999-08-03',100600,29),
('1999-08-04',100600,13), ('1999-08-05',100500,42), ('1999-08-05',100600,19),
('1999-08-06',100500,42), ('1999-08-07',100500,42), ('1999-08-08',100500,42),
('1999-08-10',100600,2), ('1999-08-10',100600,9), ('1999-08-10',100600,30),
('1999-08-11',100600,14), ('1999-08-12',100600,20), ('1999-08-17',100500,8),
('1999-08-17',100600,31), ('1999-08-18',100600,15), ('1999-08-19',100600,22),
('1999-08-24',100600,3), ('1999-08-24',100600,32), ('1999-08-27',100500,43),
('1999-08-31',100600,33), ('1999-09-17',100100,37), ('1999-09-18',100100,37),
('1999-09-19',100100,37), ('2000-12-18',100700,38);
select event_date,type,event_id from t1 WHERE event_date >= "1999-07-01" AND event_date < "1999-07-15" AND (type=100600 OR type=100100) ORDER BY event_date;
event_date	type	event_id
1999-07-10	100100	24
1999-07-11	100100	25
1999-07-13	100600	0
1999-07-13	100600	4
1999-07-13	100600	26
1999-07-14	100600	10
explain select event_date,type,event_id from t1 WHERE type = 100601 and event_date >= "1999-07-01" AND event_date < "1999-07-15" AND (type=100600 OR type=100100) ORDER BY event_date;
Comment
Impossible WHERE
select event_date,type,event_id from t1 WHERE event_date >= "1999-07-01" AND event_date <= "1999-07-15" AND (type=100600 OR type=100100) or event_date >= "1999-07-01" AND event_date <= "1999-07-15" AND type=100099;
event_date	type	event_id
1999-07-10	100100	24
1999-07-11	100100	25
1999-07-13	100600	0
1999-07-13	100600	4
1999-07-13	100600	26
1999-07-14	100600	10
1999-07-15	100600	16
drop table t1;
CREATE TABLE t1 (
PAPER_ID smallint(6) DEFAULT '0' NOT NULL,
YEAR smallint(6) DEFAULT '0' NOT NULL,
ISSUE smallint(6) DEFAULT '0' NOT NULL,
CLOSED tinyint(4) DEFAULT '0' NOT NULL,
ISS_DATE date DEFAULT '0000-00-00' NOT NULL,
PRIMARY KEY (PAPER_ID,YEAR,ISSUE)
);
INSERT INTO t1 VALUES (3,1999,34,0,'1999-07-12'), (1,1999,111,0,'1999-03-23'),
(1,1999,222,0,'1999-03-23'), (3,1999,33,0,'1999-07-12'),
(3,1999,32,0,'1999-07-12'), (3,1999,31,0,'1999-07-12'),
(3,1999,30,0,'1999-07-12'), (3,1999,29,0,'1999-07-12'),
(3,1999,28,0,'1999-07-12'), (1,1999,40,1,'1999-05-01'),
(1,1999,41,1,'1999-05-01'), (1,1999,42,1,'1999-05-01'),
(1,1999,46,1,'1999-05-01'), (1,1999,47,1,'1999-05-01'),
(1,1999,48,1,'1999-05-01'), (1,1999,49,1,'1999-05-01'),
(1,1999,50,0,'1999-05-01'), (1,1999,51,0,'1999-05-01'),
(1,1999,200,0,'1999-06-28'), (1,1999,52,0,'1999-06-28'),
(1,1999,53,0,'1999-06-28'), (1,1999,54,0,'1999-06-28'),
(1,1999,55,0,'1999-06-28'), (1,1999,56,0,'1999-07-01'),
(1,1999,57,0,'1999-07-01'), (1,1999,58,0,'1999-07-01'),
(1,1999,59,0,'1999-07-01'), (1,1999,60,0,'1999-07-01'),
(3,1999,35,0,'1999-07-12');
select YEAR,ISSUE from t1 where PAPER_ID=3 and (YEAR>1999 or (YEAR=1999 and ISSUE>28))  order by YEAR,ISSUE;
YEAR	ISSUE
1999	29
1999	30
1999	31
1999	32
1999	33
1999	34
1999	35
check table t1;
Table	Op	Msg_type	Msg_text
test.t1	check	status	OK
repair table t1;
Table	Op	Msg_type	Msg_text
test.t1	repair	status	OK
drop table t1;
CREATE TABLE t1 (
id int(11) NOT NULL auto_increment,
parent_id int(11) DEFAULT '0' NOT NULL,
level tinyint(4) DEFAULT '0' NOT NULL,
PRIMARY KEY (id),
KEY parent_id (parent_id),
KEY level (level)
);
INSERT INTO t1 VALUES (1,0,0), (3,1,1), (4,1,1), (8,2,2), (9,2,2), (17,3,2),
(22,4,2), (24,4,2), (28,5,2), (29,5,2), (30,5,2), (31,6,2), (32,6,2), (33,6,2),
(203,7,2), (202,7,2), (20,3,2), (157,0,0), (193,5,2), (40,7,2), (2,1,1),
(15,2,2), (6,1,1), (34,6,2), (35,6,2), (16,3,2), (7,1,1), (36,7,2), (18,3,2),
(26,5,2), (27,5,2), (183,4,2), (38,7,2), (25,5,2), (37,7,2), (21,4,2),
(19,3,2), (5,1,1), (179,5,2);
SELECT * FROM t1 WHERE level = 1 AND parent_id = 1;
id	parent_id	level
3	1	1
4	1	1
2	1	1
6	1	1
7	1	1
5	1	1
SELECT * FROM t1 WHERE level = 1 AND parent_id = 1 order by id;
id	parent_id	level
2	1	1
3	1	1
4	1	1
5	1	1
6	1	1
7	1	1
drop table t1;
create table t1(
Satellite		varchar(25)	not null,
SensorMode		varchar(25)	not null,
FullImageCornersUpperLeftLongitude	double	not null,
FullImageCornersUpperRightLongitude	double	not null,
FullImageCornersUpperRightLatitude	double	not null,
FullImageCornersLowerRightLatitude	double	not null,
index two (Satellite, SensorMode, FullImageCornersUpperLeftLongitude, FullImageCornersUpperRightLongitude, FullImageCornersUpperRightLatitude, FullImageCornersLowerRightLatitude));
insert into t1 values("OV-3","PAN1",91,-92,40,50);
insert into t1 values("OV-4","PAN1",91,-92,40,50);
select * from t1 where t1.Satellite = "OV-3" and t1.SensorMode = "PAN1" and t1.FullImageCornersUpperLeftLongitude > -90.000000 and t1.FullImageCornersUpperRightLongitude < -82.000000;
Satellite	SensorMode	FullImageCornersUpperLeftLongitude	FullImageCornersUpperRightLongitude	FullImageCornersUpperRightLatitude	FullImageCornersLowerRightLatitude
OV-3	PAN1	91	-92	40	50
drop table t1;
create table t1 ( aString char(100) not null default "", key aString (aString(10)) );
insert t1 (aString) values ( "believe in myself" ), ( "believe" ), ("baaa" ), ( "believe in love");
select * from t1 where aString < "believe in myself" order by aString;
aString
baaa
believe
believe in love
select * from t1 where aString > "believe in love" order by aString;
aString
believe in myself
alter table t1 drop key aString;
select * from t1 where aString < "believe in myself" order by aString;
aString
baaa
believe
believe in love
select * from t1 where aString > "believe in love" order by aString;
aString
believe in myself
drop table t1;
CREATE TABLE t1 (
t1ID int(10) unsigned NOT NULL auto_increment,
art char(1) binary NOT NULL default '',
KNR char(5) NOT NULL default '',
RECHNR char(6) NOT NULL default '',
POSNR char(2) NOT NULL default '',
ARTNR char(10) NOT NULL default '',
TEX char(70) NOT NULL default '',
PRIMARY KEY  (t1ID),
KEY IdxArt (art),
KEY IdxKnr (KNR),
KEY IdxArtnr (ARTNR)
) TYPE=MyISAM;
INSERT INTO t1 (art) VALUES ('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),('j'),('J'),
('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),
('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),
('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),
('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),
('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),
('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),
('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),
('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),
('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),
('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),
('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j'),('j');
select count(*) from t1 where upper(art) = 'J';
count(*)
602
select count(*) from t1 where art = 'J' or art = 'j';
count(*)
602
select count(*) from t1 where art = 'j' or art = 'J';
count(*)
602
select count(*) from t1 where art = 'j';
count(*)
389
select count(*) from t1 where art = 'J';
count(*)
213
drop table t1;
create table t1 ( id1 int not null, id2 int not null, idnull int null, c char(20), primary key (id1,id2));
insert into t1 values (0,1,NULL,"aaa"), (1,1,NULL,"aaa"), (2,1,NULL,"aaa"),
(3,1,NULL,"aaa"), (4,1,NULL,"aaa"), (5,1,NULL,"aaa"),
(6,1,NULL,"aaa"), (7,1,NULL,"aaa"), (8,1,NULL,"aaa"),
(9,1,NULL,"aaa"), (10,1,NULL,"aaa"), (11,1,NULL,"aaa"),
(12,1,NULL,"aaa"), (13,1,NULL,"aaa"), (14,1,NULL,"aaa"),
(15,1,NULL,"aaa"), (16,1,NULL,"aaa"), (17,1,NULL,"aaa"),
(18,1,NULL,"aaa"), (19,1,NULL,"aaa"), (20,1,NULL,"aaa");
select a.id1, b.idnull from t1 as a, t1 as b where a.id2=1 and a.id1=1 and b.id1=a.idnull order by b.id2 desc limit 1;
id1	idnull
drop table t1;
create table t1 (x int, y int, index(x), index(y));
insert into t1 (x) values (1),(2),(3),(4),(5),(6),(7),(8),(9);
update t1 set y=x;
explain select * from t1, t1 t2 where t1.y = 2 and t2.x between 7 and t1.y+0;
table	type	possible_keys	key	key_len	ref	rows	Extra
t1	ref	y	y	5	const	1	Using where
t2	range	x	x	5	NULL	4	Using where
explain select * from t1, t1 t2 where t1.y = 2 and t2.x >= 7 and t2.x <= t1.y+0;
table	type	possible_keys	key	key_len	ref	rows	Extra
t1	ref	y	y	5	const	1	Using where
t2	range	x	x	5	NULL	4	Using where
explain select * from t1, t1 t2 where t1.y = 2 and t2.x between t1.y-1 and t1.y+1;
table	type	possible_keys	key	key_len	ref	rows	Extra
t1	ref	y	y	5	const	1	Using where
t2	ALL	x	NULL	NULL	NULL	9	Using where
explain select * from t1, t1 t2 where t1.y = 2 and t2.x >= t1.y-1 and t2.x <= t1.y+1;
table	type	possible_keys	key	key_len	ref	rows	Extra
t1	ref	y	y	5	const	1	Using where
t2	ALL	x	NULL	NULL	NULL	9	Range checked for each record (index map: 1)
explain select * from t1, t1 t2 where t1.y = 2 and t2.x between 0 and t1.y;
table	type	possible_keys	key	key_len	ref	rows	Extra
t1	ref	y	y	5	const	1	Using where
t2	ALL	x	NULL	NULL	NULL	9	Using where
explain select * from t1, t1 t2 where t1.y = 2 and t2.x >= 0 and t2.x <= t1.y;
table	type	possible_keys	key	key_len	ref	rows	Extra
t1	ref	y	y	5	const	1	Using where
t2	range	x	x	5	NULL	2	Using where
drop table t1;