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drop table if exists t1,t2,t3;
SET SQL_WARNINGS=1;
CREATE TABLE t1 (
ID CHAR(32) NOT NULL,
name CHAR(32) NOT NULL,
value CHAR(255),
INDEX indexIDname (ID(8),name(8))
) ;
INSERT INTO t1 VALUES
('keyword','indexdir','/export/home/local/www/database/indexes/keyword');
INSERT INTO t1 VALUES ('keyword','urlprefix','text/ /text');
INSERT INTO t1 VALUES ('keyword','urlmap','/text/ /');
INSERT INTO t1 VALUES ('keyword','attr','personal employee company');
INSERT INTO t1 VALUES
('emailgids','indexdir','/export/home/local/www/database/indexes/emailgids');
INSERT INTO t1 VALUES ('emailgids','urlprefix','text/ /text');
INSERT INTO t1 VALUES ('emailgids','urlmap','/text/ /');
INSERT INTO t1 VALUES ('emailgids','attr','personal employee company');
SELECT value FROM t1 WHERE ID='emailgids' AND name='attr';
value
personal employee company
drop table t1;
CREATE TABLE t1 (
price int(5) DEFAULT '0' NOT NULL,
area varchar(40) DEFAULT '' NOT NULL,
type varchar(40) DEFAULT '' NOT NULL,
transityes enum('Y','N') DEFAULT 'Y' NOT NULL,
shopsyes enum('Y','N') DEFAULT 'Y' NOT NULL,
schoolsyes enum('Y','N') DEFAULT 'Y' NOT NULL,
petsyes enum('Y','N') DEFAULT 'Y' NOT NULL,
KEY price (price,area,type,transityes,shopsyes,schoolsyes,petsyes)
);
INSERT INTO t1 VALUES (900,'Vancouver','Shared/Roomate','N','N','N','N');
INSERT INTO t1 VALUES (900,'Vancouver','Shared/Roomate','N','N','N','N');
INSERT INTO t1 VALUES (900,'Vancouver','Shared/Roomate','','','','');
Warnings:
Warning 1265 Data truncated for column 'transityes' at row 1
Warning 1265 Data truncated for column 'shopsyes' at row 1
Warning 1265 Data truncated for column 'schoolsyes' at row 1
Warning 1265 Data truncated for column 'petsyes' at row 1
INSERT INTO t1 VALUES (900,'Vancouver','Shared/Roomate','Y','Y','Y','Y');
INSERT INTO t1 VALUES (900,'Vancouver','Shared/Roomate','Y','Y','Y','Y');
INSERT INTO t1 VALUES (900,'Vancouver','Shared/Roomate','Y','Y','Y','Y');
INSERT INTO t1 VALUES (900,'Vancouver','Shared/Roomate','Y','Y','Y','Y');
INSERT INTO t1 VALUES (900,'Vancouver','Shared/Roomate','Y','Y','Y','Y');
SELECT * FROM t1 WHERE area='Vancouver' and transityes='y' and schoolsyes='y' and ( ((type='1 Bedroom' or type='Studio/Bach') and (price<=500)) or ((type='2 Bedroom') and (price<=550)) or ((type='Shared/Roomate') and (price<=300)) or ((type='Room and Board') and (price<=500)) ) and price <= 400;
price area type transityes shopsyes schoolsyes petsyes
drop table t1;
CREATE TABLE t1 (program enum('signup','unique','sliding') not null, type enum('basic','sliding','signup'), sites set('mt'), PRIMARY KEY (program));
ALTER TABLE t1 modify program enum('signup','unique','sliding');
drop table t1;
CREATE TABLE t1 (
name varchar(50) DEFAULT '' NOT NULL,
author varchar(50) DEFAULT '' NOT NULL,
category decimal(10,0) DEFAULT '0' NOT NULL,
email varchar(50),
password varchar(50),
proxy varchar(50),
bitmap varchar(20),
msg varchar(255),
urlscol varchar(127),
urlhttp varchar(127),
timeout decimal(10,0),
nbcnx decimal(10,0),
creation decimal(10,0),
livinguntil decimal(10,0),
lang decimal(10,0),
type decimal(10,0),
subcat decimal(10,0),
subtype decimal(10,0),
reg char(1),
scs varchar(255),
capacity decimal(10,0),
userISP varchar(50),
CCident varchar(50) DEFAULT '' NOT NULL,
PRIMARY KEY (name,author,category)
);
INSERT INTO t1 VALUES
('patnom','patauteur',0,'p.favre@cryo-networks.fr',NULL,NULL,'#p2sndnq6ae5g1u6t','essai salut','scol://195.242.78.119:patauteur.patnom',NULL,NULL,NULL,950036174,-882087474,NULL,3,0,3,'1','Pub/patnom/futur_divers.scs',NULL,'pat','CC1');
INSERT INTO t1 VALUES
('LeNomDeMonSite','Marc',0,'m.barilley@cryo-networks.fr',NULL,NULL,NULL,NULL,'scol://195.242.78.119:Marc.LeNomDeMonSite',NULL,NULL,NULL,950560434,-881563214,NULL,3,0,3,'1','Pub/LeNomDeMonSite/domus_hibere.scs',NULL,'Marq','CC1');
select * from t1 where name='patnom' and author='patauteur' and category=0;
name author category email password proxy bitmap msg urlscol urlhttp timeout nbcnx creation livinguntil lang type subcat subtype reg scs capacity userISP CCident
patnom patauteur 0 p.favre@cryo-networks.fr NULL NULL #p2sndnq6ae5g1u6t essai salut scol://195.242.78.119:patauteur.patnom NULL NULL NULL 950036174 -882087474 NULL 3 0 3 1 Pub/patnom/futur_divers.scs NULL pat CC1
drop table t1;
create table t1
(
name_id int not null auto_increment,
name blob,
INDEX name_idx (name(5)),
primary key (name_id)
);
INSERT t1 VALUES(NULL,'/');
INSERT t1 VALUES(NULL,'[T,U]_axpby');
SELECT * FROM t1 WHERE name='[T,U]_axpy';
name_id name
SELECT * FROM t1 WHERE name='[T,U]_axpby';
name_id name
2 [T,U]_axpby
create table t2
(
name_id int not null auto_increment,
name char(255) binary,
INDEX name_idx (name(5)),
primary key (name_id)
);
INSERT t2 select * from t1;
SELECT * FROM t2 WHERE name='[T,U]_axpy';
name_id name
SELECT * FROM t2 WHERE name='[T,U]_axpby';
name_id name
2 [T,U]_axpby
drop table t1,t2;
create table t1
(
SEQNO numeric(12 ) not null,
MOTYPEID numeric(12 ) not null,
MOINSTANCEID numeric(12 ) not null,
ATTRID numeric(12 ) not null,
VALUE varchar(120) not null,
primary key (SEQNO, MOTYPEID, MOINSTANCEID, ATTRID, VALUE )
);
INSERT INTO t1 VALUES (1, 1, 1, 1, 'a');
INSERT INTO t1 VALUES (1, 1, 1, 1, 'b');
INSERT INTO t1 VALUES (1, 1, 1, 1, 'a');
ERROR 23000: Duplicate entry '1-1-1-1-a' for key 1
drop table t1;
CREATE TABLE t1 (
a tinytext NOT NULL,
b tinyint(3) unsigned NOT NULL default '0',
PRIMARY KEY (a(32),b)
) ENGINE=MyISAM;
INSERT INTO t1 VALUES ('a',1),('a',2);
SELECT * FROM t1 WHERE a='a' AND b=2;
a b
a 2
SELECT * FROM t1 WHERE a='a' AND b in (2);
a b
a 2
SELECT * FROM t1 WHERE a='a' AND b in (1,2);
a b
a 1
a 2
drop table t1;
create table t1 (a int not null unique, b int unique, c int, d int not null primary key, key(c), e int not null unique);
show keys from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 0 PRIMARY 1 d A 0 NULL NULL BTREE
t1 0 a 1 a A 0 NULL NULL BTREE
t1 0 e 1 e A 0 NULL NULL BTREE
t1 0 b 1 b A NULL NULL NULL YES BTREE
t1 1 c 1 c A NULL NULL NULL YES BTREE
drop table t1;
CREATE TABLE t1 (c CHAR(10) NOT NULL,i INT NOT NULL AUTO_INCREMENT,
UNIQUE (c,i));
INSERT INTO t1 (c) VALUES (NULL),(NULL);
Warnings:
Warning 1263 Data truncated; NULL supplied to NOT NULL column 'c' at row 1
Warning 1263 Data truncated; NULL supplied to NOT NULL column 'c' at row 2
SELECT * FROM t1;
c i
1
2
INSERT INTO t1 (c) VALUES ('a'),('a');
SELECT * FROM t1;
c i
1
2
a 1
a 2
DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (c CHAR(10) NULL, i INT NOT NULL AUTO_INCREMENT,
UNIQUE (c,i));
INSERT INTO t1 (c) VALUES (NULL),(NULL);
SELECT * FROM t1;
c i
NULL 1
NULL 2
INSERT INTO t1 (c) VALUES ('a'),('a');
SELECT * FROM t1;
c i
NULL 1
NULL 2
a 1
a 2
drop table t1;
create table t1 (i int, a char(200), b text, unique (a), unique (b(300))) charset utf8;
insert t1 values (1, repeat('a',210), repeat('b', 310));
Warnings:
Warning 1265 Data truncated for column 'a' at row 1
insert t1 values (2, repeat(0xD0B1,215), repeat(0xD0B1, 310));
Warnings:
Warning 1265 Data truncated for column 'a' at row 1
select i, length(a), length(b), char_length(a), char_length(b) from t1;
i length(a) length(b) char_length(a) char_length(b)
1 200 310 200 310
2 400 620 200 310
select i from t1 where a=repeat(_utf8 'a',200);
i
1
select i from t1 where a=repeat(_utf8 0xD0B1,200);
i
2
select i from t1 where b=repeat(_utf8 'b',310);
i
1
drop table t1;
CREATE TABLE t1 (id int unsigned auto_increment, name char(50), primary key (id)) engine=myisam;
insert into t1 (name) values ('a'), ('b'),('c'),('d'),('e'),('f'),('g');
explain select 1 from t1 where id =2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 const PRIMARY PRIMARY 4 const 1 Using index
explain select 1 from t1 where id =2 or id=3;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range PRIMARY PRIMARY 4 NULL 2 Using where; Using index
explain select name from t1 where id =2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 const PRIMARY PRIMARY 4 const 1
ALTER TABLE t1 DROP PRIMARY KEY, ADD INDEX (id);
explain select 1 from t1 where id =2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref id id 4 const 1 Using where; Using index
drop table t1;
CREATE TABLE t1 (numeropost mediumint(8) unsigned NOT NULL default '0', numreponse int(10) unsigned NOT NULL auto_increment, PRIMARY KEY (numeropost,numreponse), UNIQUE KEY numreponse (numreponse));
INSERT INTO t1 (numeropost,numreponse) VALUES ('1','1'),('1','2'),('2','3'),('2','4');
SELECT numeropost FROM t1 WHERE numreponse='1';
numeropost
1
EXPLAIN SELECT numeropost FROM t1 WHERE numreponse='1';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 const numreponse numreponse 4 const 1 Using index
FLUSH TABLES;
SELECT numeropost FROM t1 WHERE numreponse='1';
numeropost
1
drop table t1;
create table t1 (c varchar(30) character set utf8, t text character set utf8, unique (c(2)), unique (t(3))) engine=myisam;
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`c` varchar(30) character set utf8 default NULL,
`t` text character set utf8,
UNIQUE KEY `c` (`c`(2)),
UNIQUE KEY `t` (`t`(3))
) ENGINE=MyISAM DEFAULT CHARSET=latin1
insert t1 values ('cccc', 'tttt'),
(0xD0B1212223D0B1D0B1D0B1D0B1D0B1, 0xD0B1D0B1212223D0B1D0B1D0B1D0B1),
(0xD0B1222123D0B1D0B1D0B1D0B1D0B1, 0xD0B1D0B1222123D0B1D0B1D0B1D0B1);
insert t1 (c) values ('cc22');
ERROR 23000: Duplicate entry 'cc22' for key 1
insert t1 (t) values ('ttt22');
ERROR 23000: Duplicate entry 'ttt22' for key 2
insert t1 (c) values (0xD0B1212322D0B1D0B1D0B1D0B1D0B1);
ERROR 23000: Duplicate entry 'б!#"Ð' for key 1
insert t1 (t) values (0xD0B1D0B1212322D0B1D0B1D0B1D0B1);
ERROR 23000: Duplicate entry 'бб!#"б' for key 2
select c from t1 where c='cccc';
c
cccc
select t from t1 where t='tttt';
t
tttt
select c from t1 where c=0xD0B1212223D0B1D0B1D0B1D0B1D0B1;
c
?!"#?????
select t from t1 where t=0xD0B1D0B1212223D0B1D0B1D0B1D0B1;
t
??!"#????
drop table t1;
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