drop table if exists t1, t2, t3; 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; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE NULL NULL NULL NULL NULL NULL NULL 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 binary(1) 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) ) ENGINE=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(*) 213 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 (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 = 8 and t2.x between 7 and t1.y+0; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref y y 5 const 1 Using where 1 SIMPLE t2 range x x 5 NULL 2 Using where explain select * from t1, t1 t2 where t1.y = 8 and t2.x >= 7 and t2.x <= t1.y+0; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref y y 5 const 1 Using where 1 SIMPLE t2 range x x 5 NULL 2 Using where explain select * from t1, t1 t2 where t1.y = 2 and t2.x between t1.y-1 and t1.y+1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref y y 5 const 1 Using where 1 SIMPLE t2 range x x 5 NULL 3 Using where explain select * from t1, t1 t2 where t1.y = 2 and t2.x >= t1.y-1 and t2.x <= t1.y+1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref y y 5 const 1 Using where 1 SIMPLE t2 range x x 5 NULL 3 Using where explain select * from t1, t1 t2 where t1.y = 2 and t2.x between 0 and t1.y; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref y y 5 const 1 Using where 1 SIMPLE t2 range x x 5 NULL 2 Using where explain select * from t1, t1 t2 where t1.y = 2 and t2.x >= 0 and t2.x <= t1.y; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref y y 5 const 1 Using where 1 SIMPLE t2 range x x 5 NULL 2 Using where explain select count(*) from t1 where x in (1); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref x x 5 const 1 Using where; Using index explain select count(*) from t1 where x in (1,2); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index x x 5 NULL 9 Using where; Using index drop table t1; CREATE TABLE t1 (key1 int(11) NOT NULL default '0', KEY i1 (key1)); INSERT INTO t1 VALUES (0),(0),(0),(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 0; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range uid_index uid_index 4 NULL 112 Using where 1 SIMPLE t2 ref uid_index uid_index 4 test.t1.uid 38 explain select * from t1, t2 where t1.uid=t2.uid AND t2.uid > 0; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range uid_index uid_index 4 NULL 112 Using where 1 SIMPLE t2 ref uid_index uid_index 4 test.t1.uid 38 explain select * from t1, t2 where t1.uid=t2.uid AND t1.uid != 0; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range uid_index uid_index 4 NULL 113 Using where 1 SIMPLE t2 ref uid_index uid_index 4 test.t1.uid 38 explain select * from t1, t2 where t1.uid=t2.uid AND t2.uid != 0; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range uid_index uid_index 4 NULL 113 Using where 1 SIMPLE t2 ref uid_index uid_index 4 test.t1.uid 38 select * from t1, t2 where t1.uid=t2.uid AND t1.uid > 0; id name uid id name uid 1001 A 1 1001 A 1 1002 B 2 1002 B 2 1003 C 3 1003 C 3 1004 D 4 1004 D 4 1005 E 5 1005 E 5 1006 F 6 1006 F 6 1007 G 7 1007 G 7 1008 H 8 1008 H 8 1009 I 9 1009 I 9 1010 J 10 1010 J 10 1011 K 11 1011 K 11 1012 L 12 1012 L 12 1013 M 13 1013 M 13 1014 N 14 1014 N 14 1015 O 15 1015 O 15 1016 P 16 1016 P 16 1017 Q 17 1017 Q 17 1018 R 18 1018 R 18 1019 S 19 1019 S 19 1020 T 20 1020 T 20 1021 U 21 1021 U 21 1022 V 22 1022 V 22 1023 W 23 1023 W 23 1024 X 24 1024 X 24 1025 Y 25 1025 Y 25 1026 Z 26 1026 Z 26 select * from t1, t2 where t1.uid=t2.uid AND t1.uid != 0; id name uid id name uid 1001 A 1 1001 A 1 1002 B 2 1002 B 2 1003 C 3 1003 C 3 1004 D 4 1004 D 4 1005 E 5 1005 E 5 1006 F 6 1006 F 6 1007 G 7 1007 G 7 1008 H 8 1008 H 8 1009 I 9 1009 I 9 1010 J 10 1010 J 10 1011 K 11 1011 K 11 1012 L 12 1012 L 12 1013 M 13 1013 M 13 1014 N 14 1014 N 14 1015 O 15 1015 O 15 1016 P 16 1016 P 16 1017 Q 17 1017 Q 17 1018 R 18 1018 R 18 1019 S 19 1019 S 19 1020 T 20 1020 T 20 1021 U 21 1021 U 21 1022 V 22 1022 V 22 1023 W 23 1023 W 23 1024 X 24 1024 X 24 1025 Y 25 1025 Y 25 1026 Z 26 1026 Z 26 drop table t1,t2; create table t1 (x bigint unsigned not null); insert into t1(x) values (0xfffffffffffffff0); insert into t1(x) values (0xfffffffffffffff1); select * from t1; x 18446744073709551600 18446744073709551601 select count(*) from t1 where x>0; count(*) 2 select count(*) from t1 where x=0; count(*) 0 select count(*) from t1 where x<0; count(*) 0 select count(*) from t1 where x < -16; count(*) 0 select count(*) from t1 where x = -16; count(*) 0 select count(*) from t1 where x > -16; count(*) 2 select count(*) from t1 where x = 18446744073709551601; count(*) 1 create table t2 (x bigint not null); insert into t2(x) values (-16); insert into t2(x) values (-15); select * from t2; x -16 -15 select count(*) from t2 where x>0; count(*) 0 select count(*) from t2 where x=0; count(*) 0 select count(*) from t2 where x<0; count(*) 2 select count(*) from t2 where x < -16; count(*) 0 select count(*) from t2 where x = -16; count(*) 1 select count(*) from t2 where x > -16; count(*) 1 select count(*) from t2 where x = 18446744073709551601; count(*) 0 drop table t1,t2; create table t1 (x bigint unsigned not null primary key) engine=innodb; insert into t1(x) values (0xfffffffffffffff0); insert into t1(x) values (0xfffffffffffffff1); select * from t1; x 18446744073709551600 18446744073709551601 select count(*) from t1 where x>0; count(*) 2 select count(*) from t1 where x=0; count(*) 0 select count(*) from t1 where x<0; count(*) 0 select count(*) from t1 where x < -16; count(*) 0 select count(*) from t1 where x = -16; count(*) 0 select count(*) from t1 where x > -16; count(*) 2 select count(*) from t1 where x = 18446744073709551601; count(*) 1 drop table t1; create table t1 (a bigint unsigned); create index t1i on t1(a); insert into t1 select 18446744073709551615; insert into t1 select 18446744073709551614; explain select * from t1 where a <> -1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index t1i t1i 9 NULL 2 Using where; Using index select * from t1 where a <> -1; a 18446744073709551614 18446744073709551615 explain select * from t1 where a > -1 or a < -1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index t1i t1i 9 NULL 2 Using where; Using index select * from t1 where a > -1 or a < -1; a 18446744073709551614 18446744073709551615 explain select * from t1 where a > -1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index t1i t1i 9 NULL 2 Using where; Using index select * from t1 where a > -1; a 18446744073709551614 18446744073709551615 explain select * from t1 where a < -1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables select * from t1 where a < -1; a drop table t1; set names latin1; create table t1 (a char(10), b text, key (a)) character set latin1; INSERT INTO t1 (a) VALUES ('111'),('222'),('222'),('222'),('222'),('444'),('aaa'),('AAA'),('bbb'); explain select * from t1 where a='aaa'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref a a 11 const 2 Using where explain select * from t1 where a=binary 'aaa'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 11 NULL 2 Using where explain select * from t1 where a='aaa' collate latin1_bin; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 11 NULL 2 Using where explain select * from t1 where a='aaa' collate latin1_german1_ci; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL a NULL NULL NULL 9 Using where drop table t1; CREATE TABLE t1 ( `CLIENT` char(3) character set latin1 collate latin1_bin NOT NULL default '000', `ARG1` char(3) character set latin1 collate latin1_bin NOT NULL default '', `ARG2` char(3) character set latin1 collate latin1_bin NOT NULL default '', `FUNCTION` varchar(10) character set latin1 collate latin1_bin NOT NULL default '', `FUNCTINT` int(11) NOT NULL default '0', KEY `VERI_CLNT~2` (`ARG1`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1; INSERT INTO t1 VALUES ('000',' 0',' 0','Text 001',0), ('000',' 0',' 1','Text 002',0), ('000',' 1',' 2','Text 003',0), ('000',' 2',' 3','Text 004',0), ('001',' 3',' 0','Text 017',0); SELECT count(*) FROM t1 WHERE CLIENT='000' AND (ARG1 != ' 1' OR ARG1 != ' 2'); count(*) 4 SELECT count(*) FROM t1 WHERE CLIENT='000' AND (ARG1 != ' 2' OR ARG1 != ' 1'); count(*) 4 drop table t1; create table t1 (a int); insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); CREATE TABLE t2 ( pk1 int(11) NOT NULL, pk2 int(11) NOT NULL, pk3 int(11) NOT NULL, pk4 int(11) NOT NULL, filler char(82), PRIMARY KEY (pk1,pk2,pk3,pk4) ) DEFAULT CHARSET=latin1; insert into t2 select 1, A.a+10*B.a, 432, 44, 'fillerZ' from t1 A, t1 B; INSERT INTO t2 VALUES (2621, 2635, 0, 0,'filler'), (2621, 2635, 1, 0,'filler'), (2621, 2635, 10, 0,'filler'), (2621, 2635, 11, 0,'filler'), (2621, 2635, 14, 0,'filler'), (2621, 2635, 1000015, 0,'filler'); SELECT * FROM t2 WHERE ((((pk4 =0) AND (pk1 =2621) AND (pk2 =2635))) OR ((pk4 =1) AND (((pk1 IN ( 7, 2, 1 ))) OR (pk1 =522)) AND ((pk2 IN ( 0, 2635)))) ) AND (pk3 >=1000000); pk1 pk2 pk3 pk4 filler 2621 2635 1000015 0 filler drop table t1, t2; create table t1(a char(2), key(a(1))); insert into t1 values ('x'), ('xx'); explain select a from t1 where a > 'x'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 2 NULL 2 Using where select a from t1 where a > 'x'; a xx drop table t1; CREATE TABLE t1 ( OXID varchar(32) COLLATE latin1_german2_ci NOT NULL DEFAULT '', OXPARENTID varchar(32) COLLATE latin1_german2_ci NOT NULL DEFAULT 'oxrootid', OXLEFT int NOT NULL DEFAULT '0', OXRIGHT int NOT NULL DEFAULT '0', OXROOTID varchar(32) COLLATE latin1_german2_ci NOT NULL DEFAULT '', PRIMARY KEY (OXID), KEY OXNID (OXID), KEY OXLEFT (OXLEFT), KEY OXRIGHT (OXRIGHT), KEY OXROOTID (OXROOTID) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_german2_ci; INSERT INTO t1 VALUES ('d8c4177d09f8b11f5.52725521','oxrootid',1,40,'d8c4177d09f8b11f5.52725521'), ('d8c4177d151affab2.81582770','d8c4177d09f8b11f5.52725521',2,3, 'd8c4177d09f8b11f5.52725521'), ('d8c4177d206a333d2.74422679','d8c4177d09f8b11f5.52725521',4,5, 'd8c4177d09f8b11f5.52725521'), ('d8c4177d225791924.30714720','d8c4177d09f8b11f5.52725521',6,7, 'd8c4177d09f8b11f5.52725521'), ('d8c4177d2380fc201.39666693','d8c4177d09f8b11f5.52725521',8,9, 'd8c4177d09f8b11f5.52725521'), ('d8c4177d24ccef970.14957924','d8c4177d09f8b11f5.52725521',10,11, 'd8c4177d09f8b11f5.52725521'); EXPLAIN SELECT s.oxid FROM t1 v, t1 s WHERE s.oxrootid = 'd8c4177d09f8b11f5.52725521' AND v.oxrootid ='d8c4177d09f8b11f5.52725521' AND s.oxleft > v.oxleft AND s.oxleft < v.oxright; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE v ref OXLEFT,OXRIGHT,OXROOTID OXROOTID 34 const 5 Using where 1 SIMPLE s ALL OXLEFT NULL NULL NULL 5 Range checked for each record (index map: 0x4) SELECT s.oxid FROM t1 v, t1 s WHERE s.oxrootid = 'd8c4177d09f8b11f5.52725521' AND v.oxrootid ='d8c4177d09f8b11f5.52725521' AND s.oxleft > v.oxleft AND s.oxleft < v.oxright; oxid d8c4177d151affab2.81582770 d8c4177d206a333d2.74422679 d8c4177d225791924.30714720 d8c4177d2380fc201.39666693 d8c4177d24ccef970.14957924 DROP TABLE t1; create table t1 ( c1 char(10), c2 char(10), c3 char(10), c4 char(10), c5 char(10), c6 char(10), c7 char(10), c8 char(10), c9 char(10), c10 char(10), c11 char(10), c12 char(10), c13 char(10), c14 char(10), c15 char(10), c16 char(10), index(c1, c2, c3, c4, c5, c6, c7, c8, c9, c10, c11, c12,c13,c14,c15,c16) ); insert into t1 (c1) values ('1'),('1'),('1'),('1'); select * from t1 where c1 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC") and c2 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC") and c3 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC") and c4 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC") and c5 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC") and c6 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC") and c7 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC") and c8 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC") and c9 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC") and c10 in ("abcdefgh", "123456789", "qwertyuio", "asddfgh", "abcdefg1", "123456781", "qwertyui1", "asddfg1", "abcdefg2", "123456782", "qwertyui2", "asddfg2", "abcdefg3", "123456783", "qwertyui3", "asddfg3", "abcdefg4", "123456784", "qwertyui4", "asddfg4", "abcdefg5", "123456785", "qwertyui5", "asddfg5", "abcdefg6", "123456786", "qwertyui6", "asddfg6", "abcdefg7", "123456787", "qwertyui7", "asddfg7", "abcdefg8", "123456788", "qwertyui8", "asddfg8", "abcdefg9", "123456789", "qwertyui9", "asddfg9", "abcdefgA", "12345678A", "qwertyuiA", "asddfgA", "abcdefgB", "12345678B", "qwertyuiB", "asddfgB", "abcdefgC", "12345678C", "qwertyuiC", "asddfgC"); c1 c2 c3 c4 c5 c6 c7 c8 c9 c10 c11 c12 c13 c14 c15 c16 drop table t1; End of 4.1 tests CREATE TABLE t1 ( id int(11) NOT NULL auto_increment, status varchar(20), PRIMARY KEY (id), KEY (status) ); INSERT INTO t1 VALUES (1,'B'), (2,'B'), (3,'B'), (4,'B'), (5,'B'), (6,'B'), (7,'B'), (8,'B'), (9,'B'), (10,'B'), (11,'B'), (12,'B'), (13,'B'), (14,'B'), (15,'B'), (16,'B'), (17,'B'), (18,'B'), (19,'B'), (20,'B'), (21,'B'), (22,'B'), (23,'B'), (24,'B'), (25,'A'), (26,'A'), (27,'A'), (28,'A'), (29,'A'), (30,'A'), (31,'A'), (32,'A'), (33,'A'), (34,'A'), (35,'A'), (36,'A'), (37,'A'), (38,'A'), (39,'A'), (40,'A'), (41,'A'), (42,'A'), (43,'A'), (44,'A'), (45,'A'), (46,'A'), (47,'A'), (48,'A'), (49,'A'), (50,'A'), (51,'A'), (52,'A'), (53,'C'), (54,'C'), (55,'C'), (56,'C'), (57,'C'), (58,'C'), (59,'C'), (60,'C'); EXPLAIN SELECT * FROM t1 WHERE status <> 'A' AND status <> 'B'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range status status 23 NULL 11 Using where EXPLAIN SELECT * FROM t1 WHERE status NOT IN ('A','B'); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range status status 23 NULL 11 Using where SELECT * FROM t1 WHERE status <> 'A' AND status <> 'B'; id status 53 C 54 C 55 C 56 C 57 C 58 C 59 C 60 C SELECT * FROM t1 WHERE status NOT IN ('A','B'); id status 53 C 54 C 55 C 56 C 57 C 58 C 59 C 60 C EXPLAIN SELECT status FROM t1 WHERE status <> 'A' AND status <> 'B'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range status status 23 NULL 11 Using where; Using index EXPLAIN SELECT status FROM t1 WHERE status NOT IN ('A','B'); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range status status 23 NULL 11 Using where; Using index EXPLAIN SELECT * FROM t1 WHERE status NOT BETWEEN 'A' AND 'B'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range status status 23 NULL 10 Using where EXPLAIN SELECT * FROM t1 WHERE status < 'A' OR status > 'B'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range status status 23 NULL 10 Using where SELECT * FROM t1 WHERE status NOT BETWEEN 'A' AND 'B'; id status 53 C 54 C 55 C 56 C 57 C 58 C 59 C 60 C SELECT * FROM t1 WHERE status < 'A' OR status > 'B'; id status 53 C 54 C 55 C 56 C 57 C 58 C 59 C 60 C DROP TABLE t1; CREATE TABLE t1 (a int, b int, primary key(a,b)); INSERT INTO t1 VALUES (1,1),(1,2),(1,3),(2,1),(2,2),(2,3),(3,1),(3,2),(3,3),(4,1),(4,2),(4,3); CREATE VIEW v1 as SELECT a,b FROM t1 WHERE b=3; EXPLAIN SELECT a,b FROM t1 WHERE a < 2 and b=3; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range PRIMARY PRIMARY 4 NULL 4 Using where; Using index EXPLAIN SELECT a,b FROM v1 WHERE a < 2 and b=3; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range PRIMARY PRIMARY 4 NULL 4 Using where; Using index EXPLAIN SELECT a,b FROM t1 WHERE a < 2; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range PRIMARY PRIMARY 4 NULL 4 Using where; Using index EXPLAIN SELECT a,b FROM v1 WHERE a < 2; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range PRIMARY PRIMARY 4 NULL 4 Using where; Using index SELECT a,b FROM t1 WHERE a < 2 and b=3; a b 1 3 SELECT a,b FROM v1 WHERE a < 2 and b=3; a b 1 3 DROP VIEW v1; DROP TABLE t1; CREATE TABLE t1 (name varchar(15) NOT NULL, KEY idx(name)); INSERT INTO t1 VALUES ('Betty'), ('Anna'); SELECT * FROM t1; name Anna Betty DELETE FROM t1 WHERE name NOT LIKE 'A%a'; SELECT * FROM t1; name Anna DROP TABLE t1; CREATE TABLE t1 (a int, KEY idx(a)); INSERT INTO t1 VALUES (NULL), (1), (2), (3); SELECT * FROM t1; a NULL 1 2 3 DELETE FROM t1 WHERE NOT(a <=> 2); SELECT * FROM t1; a 2 DROP TABLE t1; create table t1 (a int, b int, primary key(a,b)); create view v1 as select a, b from t1; INSERT INTO `t1` VALUES (0,0),(1,0),(2,0),(3,0),(4,0),(5,1),(6,1),(7,1),(8,1),(9,1),(10,2),(11,2),(12,2) ,(13,2),(14,2),(15,3),(16,3),(17,3),(18,3),(19,3); explain select * from t1 where a in (3,4) and b in (1,2,3); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range PRIMARY PRIMARY 8 NULL # Using where; Using index explain select * from v1 where a in (3,4) and b in (1,2,3); id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range PRIMARY PRIMARY 8 NULL # Using where; Using index explain select * from t1 where a between 3 and 4 and b between 1 and 2; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range PRIMARY PRIMARY 8 NULL # Using where; Using index explain select * from v1 where a between 3 and 4 and b between 1 and 2; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range PRIMARY PRIMARY 8 NULL # Using where; Using index drop view v1; drop table t1; create table t3 (a int); insert into t3 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); create table t1 (a varchar(10), filler char(200), key(a)) charset=binary; insert into t1 values ('a',''); insert into t1 values ('a ',''); insert into t1 values ('a ', ''); insert into t1 select concat('a', 1000 + A.a + 10 * (B.a + 10 * C.a)), '' from t3 A, t3 B, t3 C; create table t2 (a varchar(10), filler char(200), key(a)); insert into t2 select * from t1; explain select * from t1 where a between 'a' and 'a '; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 13 NULL # Using where explain select * from t1 where a = 'a' or a='a '; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 13 NULL # Using where explain select * from t2 where a between 'a' and 'a '; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 ref a a 13 const # Using where explain select * from t2 where a = 'a' or a='a '; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 ref a a 13 const # Using where update t1 set a='b' where a<>'a'; explain select * from t1 where a not between 'b' and 'b'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 13 NULL # Using where select a, hex(filler) from t1 where a not between 'b' and 'b'; a hex(filler) a 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 drop table t1,t2,t3; create table t1 (a int); insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); create table t2 (a int, key(a)); insert into t2 select 2*(A.a + 10*(B.a + 10*C.a)) from t1 A, t1 B, t1 C; set @a="select * from t2 force index (a) where a NOT IN(0"; select count(*) from (select @a:=concat(@a, ',', a) from t2 ) Z; count(*) 1000 set @a=concat(@a, ')'); insert into t2 values (11),(13),(15); set @b= concat("explain ", @a); prepare stmt1 from @b; execute stmt1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 index a a 5 NULL 1003 Using where; Using index prepare stmt1 from @a; execute stmt1; a 11 13 15 drop table t1, t2; CREATE TABLE t1 ( id int NOT NULL DEFAULT '0', b int NOT NULL DEFAULT '0', c int NOT NULL DEFAULT '0', INDEX idx1(b,c), INDEX idx2(c)); INSERT INTO t1(id) VALUES (1), (2), (3), (4), (5), (6), (7), (8); INSERT INTO t1(b,c) VALUES (3,4), (3,4); SELECT * FROM t1 WHERE b<=3 AND 3<=c; id b c 0 3 4 0 3 4 SELECT * FROM t1 WHERE 3 BETWEEN b AND c; id b c 0 3 4 0 3 4 EXPLAIN SELECT * FROM t1 WHERE b<=3 AND 3<=c; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range idx1,idx2 idx2 4 NULL 3 Using where EXPLAIN SELECT * FROM t1 WHERE 3 BETWEEN b AND c; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range idx1,idx2 idx2 4 NULL 3 Using where SELECT * FROM t1 WHERE 0 < b OR 0 > c; id b c 0 3 4 0 3 4 SELECT * FROM t1 WHERE 0 NOT BETWEEN b AND c; id b c 0 3 4 0 3 4 EXPLAIN SELECT * FROM t1 WHERE 0 < b OR 0 > c; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index_merge idx1,idx2 idx1,idx2 4,4 NULL 4 Using sort_union(idx1,idx2); Using where EXPLAIN SELECT * FROM t1 WHERE 0 NOT BETWEEN b AND c; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 index_merge idx1,idx2 idx1,idx2 4,4 NULL 4 Using sort_union(idx1,idx2); Using where DROP TABLE t1; CREATE TABLE t1 ( item char(20) NOT NULL default '', started datetime NOT NULL default '0000-00-00 00:00:00', price decimal(16,3) NOT NULL default '0.000', PRIMARY KEY (item,started) ) ENGINE=MyISAM; INSERT INTO t1 VALUES ('A1','2005-11-01 08:00:00',1000), ('A1','2005-11-15 00:00:00',2000), ('A1','2005-12-12 08:00:00',3000), ('A2','2005-12-01 08:00:00',1000); EXPLAIN SELECT * FROM t1 WHERE item='A1' AND started<='2005-12-01 24:00:00'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref PRIMARY PRIMARY 20 const 2 Using where Warnings: Warning 1292 Incorrect datetime value: '2005-12-01 24:00:00' for column 'started' at row 1 Warning 1292 Incorrect datetime value: '2005-12-01 24:00:00' for column 'started' at row 1 SELECT * FROM t1 WHERE item='A1' AND started<='2005-12-01 24:00:00'; item started price A1 2005-11-01 08:00:00 1000.000 A1 2005-11-15 00:00:00 2000.000 Warnings: Warning 1292 Incorrect datetime value: '2005-12-01 24:00:00' for column 'started' at row 1 Warning 1292 Incorrect datetime value: '2005-12-01 24:00:00' for column 'started' at row 1 SELECT * FROM t1 WHERE item='A1' AND started<='2005-12-02 00:00:00'; item started price A1 2005-11-01 08:00:00 1000.000 A1 2005-11-15 00:00:00 2000.000 DROP INDEX `PRIMARY` ON t1; EXPLAIN SELECT * FROM t1 WHERE item='A1' AND started<='2005-12-01 24:00:00'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ALL NULL NULL NULL NULL 4 Using where Warnings: Warning 1292 Incorrect datetime value: '2005-12-01 24:00:00' for column 'started' at row 1 SELECT * FROM t1 WHERE item='A1' AND started<='2005-12-01 24:00:00'; item started price A1 2005-11-01 08:00:00 1000.000 A1 2005-11-15 00:00:00 2000.000 Warnings: Warning 1292 Incorrect datetime value: '2005-12-01 24:00:00' for column 'started' at row 1 SELECT * FROM t1 WHERE item='A1' AND started<='2005-12-02 00:00:00'; item started price A1 2005-11-01 08:00:00 1000.000 A1 2005-11-15 00:00:00 2000.000 DROP TABLE t1; BUG#32198 "Comparison of DATE with DATETIME still not using indexes correctly" CREATE TABLE t1 ( id int(11) NOT NULL auto_increment, dateval date default NULL, PRIMARY KEY (id), KEY dateval (dateval) ) AUTO_INCREMENT=173; INSERT INTO t1 VALUES (1,'2007-01-01'),(2,'2007-01-02'),(3,'2007-01-03'),(4,'2007-01-04'), (5,'2007-01-05'),(6,'2007-01-06'),(7,'2007-01-07'),(8,'2007-01-08'), (9,'2007-01-09'),(10,'2007-01-10'),(11,'2007-01-11'); This must use range access: explain select * from t1 where dateval >= '2007-01-01 00:00:00' and dateval <= '2007-01-02 23:59:59'; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range dateval dateval 4 NULL 2 Using where drop table t1;