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|
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 Range checked for each record (index map: 1)
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
explain select count(*) from t1 where x in (1);
table type possible_keys key key_len ref rows Extra
t1 range x x 5 NULL 1 Using where; Using index
explain select count(*) from t1 where x in (1,2);
table type possible_keys key key_len ref rows Extra
t1 range x x 5 NULL 2 Using where; Using index
drop table t1;
CREATE TABLE t1 (key1 int(11) NOT NULL default '0', KEY i1 (key1), KEY i2 (key1));
INSERT INTO t1 VALUES (0),(0),(1),(1);
CREATE TABLE t2 (keya int(11) NOT NULL default '0', KEY j1 (keya));
INSERT INTO t2 VALUES (0),(0),(1),(1),(2),(2);
explain select * from t1, t2 where (t1.key1 <t2.keya + 1) and t2.keya=3;
table type possible_keys key key_len ref rows Extra
t2 ref j1 j1 4 const 1 Using where; Using index
t1 ALL i1,i2 NULL NULL NULL 4 Range checked for each record (index map: 3)
explain select * from t1 force index(i2), t2 where (t1.key1 <t2.keya + 1) and t2.keya=3;
table type possible_keys key key_len ref rows Extra
t2 ref j1 j1 4 const 1 Using where; Using index
t1 ALL i2 NULL NULL NULL 4 Range checked for each record (index map: 2)
DROP TABLE t1,t2;
CREATE TABLE t1 (
a int(11) default NULL,
b int(11) default NULL,
KEY a (a),
KEY b (b)
) TYPE=MyISAM;
INSERT INTO t1 VALUES
(1,1),(2,1),(3,1),(4,1),(5,1),(6,1),(7,1),(8,1),(9,1),(10,2),(10,2),
(13,2),(14,2),(15,2),(16,2),(17,3),(17,3),(16,3),(17,3),(19,3),(20,3),
(21,4),(22,5),(23,5),(24,5),(25,5),(26,5),(30,5),(31,5),(32,5),(33,5),
(33,5),(33,5),(33,5),(33,5),(34,5),(35,5);
EXPLAIN SELECT * FROM t1 WHERE a IN(1,2) AND b=5;
table type possible_keys key key_len ref rows Extra
t1 range a,b a 5 NULL 2 Using where
SELECT * FROM t1 WHERE a IN(1,2) AND b=5;
a b
DROP TABLE t1;
CREATE TABLE t1 (a int, b int, c int, INDEX (c,a,b));
INSERT INTO t1 VALUES (1,0,0),(1,0,0),(1,0,0);
INSERT INTO t1 VALUES (0,1,0),(0,1,0),(0,1,0);
SELECT COUNT(*) FROM t1 WHERE (c=0 and a=1) or (c=0 and b=1);
COUNT(*)
6
SELECT COUNT(*) FROM t1 WHERE (c=0 and b=1) or (c=0 and a=1);
COUNT(*)
6
DROP TABLE t1;
CREATE TABLE t1 ( a int not null, b int not null, INDEX ab(a,b) );
INSERT INTO t1 VALUES (47,1), (70,1), (15,1), (15, 4);
SELECT * FROM t1
WHERE
(
( b =1 AND a BETWEEN 14 AND 21 ) OR
( b =2 AND a BETWEEN 16 AND 18 ) OR
( b =3 AND a BETWEEN 15 AND 19 ) OR
(a BETWEEN 19 AND 47)
);
a b
15 1
47 1
|
