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
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
|
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 DEFAULT '0' NOT NULL,
area varchar(160) DEFAULT '' NOT NULL,
type varchar(160) 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 (price, area, type) VALUES (900,'Vancouver','Shared/Roomate');
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'), 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),
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
CREATE TABLE t3 SELECT * FROM t2 WHERE name='[T,U]_axpby';
SELECT * FROM t2 WHERE name='[T,U]_axpby';
name_id name
2 [T,U]_axpby
drop table t1,t2,t3;
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 'PRIMARY'
drop table t1;
CREATE TEMPORARY TABLE t1 (
a tinytext NOT NULL,
b int 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 Unique Key_name Seq_in_index Column_name
t1 YES PRIMARY 1 d
t1 YES a 1 a
t1 YES e 1 e
t1 YES b 1 b
t1 NO c 1 c
drop table t1;
CREATE TABLE t1 (c VARCHAR(10) NOT NULL,i INT PRIMARY KEY NOT NULL AUTO_INCREMENT, UNIQUE (c,i));
INSERT INTO t1 (c) VALUES (NULL),(NULL);
ERROR 23000: Column 'c' cannot be null
SELECT * FROM t1;
c i
INSERT INTO t1 (c) VALUES ('a'),('a');
SELECT * FROM t1;
c i
a 1
a 2
DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (c CHAR(10) NULL, i INT PRIMARY KEY 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 3
a 4
drop table t1;
CREATE TEMPORARY TABLE t1 (id int 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 index PRIMARY PRIMARY 4 NULL 7 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 index
drop table t1;
CREATE TABLE t1 (numeropost int NOT NULL default '0', numreponse int 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 temporary table t1 (c varchar(30), t text, unique (c(2)), unique (t(3))) engine=myisam;
show create table t1;
Table Create Table
t1 CREATE TEMPORARY TABLE `t1` (
`c` VARCHAR(30) COLLATE utf8_general_ci DEFAULT NULL,
`t` TEXT COLLATE utf8_general_ci,
UNIQUE KEY `c` (`c`(2)),
UNIQUE KEY `t` (`t`(3))
) ENGINE=MyISAM COLLATE = utf8_general_ci
insert t1 values ('cccc', 'tttt'),
(0xD0B1212223D0B1D0B1D0B1D0B1D0B1, 0xD0B1D0B1212223D0B1D0B1D0B1D0B1),
(0xD0B1222123D0B1D0B1D0B1D0B1D0B1, 0xD0B1D0B1222123D0B1D0B1D0B1D0B1);
insert t1 (c) values ('cc22');
ERROR 23000: Duplicate entry 'cc' for key 'c'
insert t1 (t) values ('ttt22');
ERROR 23000: Duplicate entry 'ttt' for key 't'
insert t1 (c) values (0xD0B1212322D0B1D0B1D0B1D0B1D0B1);
ERROR 23000: Duplicate entry 'б!' for key 'c'
insert t1 (t) values (0xD0B1D0B1212322D0B1D0B1D0B1D0B1);
ERROR 23000: Duplicate entry 'бб!' for key 't'
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
б!"#ббббб
select t from t1 where t=0xD0B1D0B1212223D0B1D0B1D0B1D0B1;
t
бб!"#бббб
drop table t1;
DROP TABLE IF EXISTS t1;
Warnings:
Note 1051 Unknown table 't1'
CREATE TEMPORARY TABLE t1 (
c1 int,
c2 varbinary(240),
UNIQUE KEY (c1),
KEY (c2)
) ENGINE=MyISAM;
INSERT INTO t1 VALUES (1,'\Z\Z\Z\Z');
INSERT INTO t1 VALUES (2,'\Z\Z\Z\Z\Z\Z');
INSERT INTO t1 VALUES (3,'\Z\Z\Z\Z');
select c1 from t1 where c2='\Z\Z\Z\Z';
c1
1
3
DELETE FROM t1 WHERE (c1 = 1);
check table t1;
Table Op Msg_type Msg_text
test.t1 check status OK
select c1 from t1 where c2='\Z\Z\Z\Z';
c1
3
DELETE FROM t1 WHERE (c1 = 3);
check table t1;
Table Op Msg_type Msg_text
test.t1 check status OK
select c1 from t1 where c2='\Z\Z\Z\Z';
c1
truncate table t1;
insert into t1 values(1,"aaaa"),(2,"aaab"),(3,"aaac"),(4,"aaccc");
delete from t1 where c1=3;
delete from t1 where c1=1;
delete from t1 where c1=4;
check table t1;
Table Op Msg_type Msg_text
test.t1 check status OK
drop table t1;
create table t1 (c char(10), index (c(0)));
ERROR HY000: Key part 'c' length cannot be 0
create table t1 (c char(10), index (c,c));
ERROR 42S21: Duplicate column name 'c'
create table t1 (c1 char(10), c2 char(10), index (c1,c2,c1));
ERROR 42S21: Duplicate column name 'c1'
create table t1 (c1 char(10), c2 char(10), index (c1,c1,c2));
ERROR 42S21: Duplicate column name 'c1'
create table t1 (c1 char(10), c2 char(10), index (c2,c1,c1));
ERROR 42S21: Duplicate column name 'c1'
create table t1 (c1 char(10), c2 char(10));
alter table t1 add key (c1,c1);
ERROR 42S21: Duplicate column name 'c1'
alter table t1 add key (c2,c1,c1);
ERROR 42S21: Duplicate column name 'c1'
alter table t1 add key (c1,c2,c1);
ERROR 42S21: Duplicate column name 'c1'
alter table t1 add key (c1,c1,c2);
ERROR 42S21: Duplicate column name 'c1'
drop table t1;
create table t1 (
i1 INT NOT NULL,
i2 INT NOT NULL,
UNIQUE i1idx (i1),
UNIQUE i2idx (i2));
desc t1;
Field Type Null Default Default_is_NULL On_Update
i1 INTEGER NO NO
i2 INTEGER NO NO
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`i1` INT NOT NULL,
`i2` INT NOT NULL,
UNIQUE KEY `i1idx` (`i1`),
UNIQUE KEY `i2idx` (`i2`)
) ENGINE=InnoDB COLLATE = utf8_general_ci
drop table t1;
create temporary table t1 (
c1 int,
c2 varchar(20) not null,
primary key (c1),
key (c2(10))
) engine=myisam;
insert into t1 values (1,'');
insert into t1 values (2,' \t\tTest String');
insert into t1 values (3,' \n\tTest String');
update t1 set c2 = 'New Test String' where c1 = 1;
select * from t1;
c1 c2
1 New Test String
2 Test String
3
Test String
drop table t1;
create table t1 (a varchar(10), b varchar(10), key(a(10),b(10)));
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` VARCHAR(10) COLLATE utf8_general_ci DEFAULT NULL,
`b` VARCHAR(10) COLLATE utf8_general_ci DEFAULT NULL,
KEY `a` (`a`,`b`)
) ENGINE=InnoDB COLLATE = utf8_general_ci
alter table t1 modify b varchar(20);
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` VARCHAR(10) COLLATE utf8_general_ci DEFAULT NULL,
`b` VARCHAR(20) COLLATE utf8_general_ci DEFAULT NULL,
KEY `a` (`a`,`b`)
) ENGINE=InnoDB COLLATE = utf8_general_ci
alter table t1 modify a varchar(20);
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` VARCHAR(20) COLLATE utf8_general_ci DEFAULT NULL,
`b` VARCHAR(20) COLLATE utf8_general_ci DEFAULT NULL,
KEY `a` (`a`,`b`)
) ENGINE=InnoDB COLLATE = utf8_general_ci
drop table t1;
create table t1 (a int not null primary key, b varchar(20) not null unique);
desc t1;
Field Type Null Default Default_is_NULL On_Update
a INTEGER NO NO
b VARCHAR NO NO
drop table t1;
create table t1 (a int not null primary key, b int not null unique);
desc t1;
Field Type Null Default Default_is_NULL On_Update
a INTEGER NO NO
b INTEGER NO NO
drop table t1;
create table t1 (a int not null primary key, b varchar(20) not null, unique (b(10)));
desc t1;
Field Type Null Default Default_is_NULL On_Update
a INTEGER NO NO
b VARCHAR NO NO
drop table t1;
create table t1 (a int not null primary key, b varchar(20) not null, c varchar(20) not null, unique(b(10),c(10)));
desc t1;
Field Type Null Default Default_is_NULL On_Update
a INTEGER NO NO
b VARCHAR NO NO
c VARCHAR NO NO
drop table t1;
create table t1 (
c1 int,
c2 char(12),
c3 varchar(123),
c4 timestamp,
index (c1),
index i1 (c1),
index i2 (c2),
index i3 (c3),
unique i4 (c4),
index i5 (c1, c2, c3, c4),
primary key (c2, c3),
index (c2, c4));
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`c1` INT DEFAULT NULL,
`c2` VARCHAR(12) COLLATE utf8_general_ci NOT NULL,
`c3` VARCHAR(123) COLLATE utf8_general_ci NOT NULL,
`c4` TIMESTAMP NULL DEFAULT NULL,
PRIMARY KEY (`c2`,`c3`),
UNIQUE KEY `i4` (`c4`),
KEY `c1` (`c1`),
KEY `i1` (`c1`),
KEY `i2` (`c2`),
KEY `i3` (`c3`),
KEY `i5` (`c1`,`c2`,`c3`,`c4`),
KEY `c2` (`c2`,`c4`)
) ENGINE=InnoDB COLLATE = utf8_general_ci
alter table t1 drop index c1;
alter table t1 add index (c1);
alter table t1 add index (c1);
alter table t1 drop index i3;
alter table t1 add index i3 (c3);
alter table t1 drop index i2, drop index i4;
alter table t1 add index i2 (c2), add index i4 (c4);
alter table t1 drop index i2, drop index i4, add index i6 (c2, c4);
alter table t1 add index i2 (c2), add index i4 (c4), drop index i6;
alter table t1 drop index i2, drop index i4, add unique i4 (c4);
alter table t1 add index i2 (c2), drop index i4, add index i4 (c4);
alter table t1 drop index c2, add index (c2(4),c3(7));
alter table t1 drop index c2, add index (c2(4),c3(7));
alter table t1 add primary key (c1, c2), drop primary key;
alter table t1 drop primary key;
alter table t1 add primary key (c1, c2), drop primary key;
ERROR 42000: Can't DROP 'PRIMARY'; check that column/key exists
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`c1` INT NOT NULL,
`c2` VARCHAR(12) COLLATE utf8_general_ci NOT NULL,
`c3` VARCHAR(123) COLLATE utf8_general_ci NOT NULL,
`c4` TIMESTAMP NULL DEFAULT NULL,
KEY `i1` (`c1`),
KEY `i5` (`c1`,`c2`,`c3`,`c4`),
KEY `c1` (`c1`),
KEY `c1_2` (`c1`),
KEY `i3` (`c3`),
KEY `i2` (`c2`),
KEY `i4` (`c4`),
KEY `c2` (`c2`(4),`c3`(7))
) ENGINE=InnoDB COLLATE = utf8_general_ci
insert into t1 values(1, 'a', 'a', NULL);
insert into t1 values(1, 'b', 'b', NULL);
alter table t1 drop index i3, drop index i2, drop index i1;
alter table t1 add index i3 (c3), add index i2 (c2), add unique index i1 (c1);
ERROR 23000: Duplicate entry '1' for key 'i1'
drop table t1;
CREATE TEMPORARY TABLE t1( a int, KEY(a) ) ENGINE=MyISAM;
INSERT INTO t1 VALUES( 1 );
ALTER TABLE t1 DISABLE KEYS;
EXPLAIN SELECT MAX(a) FROM t1 FORCE INDEX(a);
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 system NULL NULL NULL NULL 1
drop table t1;
CREATE TABLE t1 (
a INTEGER auto_increment PRIMARY KEY,
b INTEGER NOT NULL,
c INTEGER NOT NULL,
d CHAR(64)
);
CREATE TABLE t2 (
a INTEGER auto_increment PRIMARY KEY,
b INTEGER NOT NULL,
c int NOT NULL,
d DATETIME NOT NULL,
e int NOT NULL,
f INTEGER NOT NULL,
g INTEGER NOT NULL,
h int NOT NULL,
i INTEGER NOT NULL,
j INTEGER NOT NULL,
UNIQUE INDEX (b),
INDEX (b, d, e, f, g, h, i, j, c),
INDEX (c)
);
INSERT INTO t2 VALUES
(NULL, 1, 254, '1000-01-01 00:00:00', 257, 0, 0, 0, 0, 0),
(NULL, 2, 1, '2004-11-30 12:00:00', 1, 0, 0, 0, 0, 0),
(NULL, 3, 1, '2004-11-30 12:00:00', 1, 0, 0, 2, -21600, 0),
(NULL, 4, 1, '2004-11-30 12:00:00', 1, 0, 0, 2, -10800, 0),
(NULL, 5, 1, '2004-11-30 12:00:00', 1, 0, 0, 5, -10800, 0),
(NULL, 6, 1, '2004-11-30 12:00:00', 102, 0, 0, 0, 0, 0),
(NULL, 7, 1, '2004-11-30 12:00:00', 105, 2, 0, 0, 0, 0),
(NULL, 8, 1, '2004-11-30 12:00:00', 105, 10, 0, 0, 0, 0);
INSERT INTO t1 (b, c, d) VALUES
(3388000, -553000, NULL),
(3388000, -553000, NULL);
DROP TABLE t1, t2;
create table t1(a int not null, key aa(a),
b char(10) not null, unique key bb(b(1)),
c char(4) not null, unique key cc(c));
desc t1;
Field Type Null Default Default_is_NULL On_Update
a INTEGER NO NO
b VARCHAR NO NO
c VARCHAR NO NO
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` INT NOT NULL,
`b` VARCHAR(10) COLLATE utf8_general_ci NOT NULL,
`c` VARCHAR(4) COLLATE utf8_general_ci NOT NULL,
UNIQUE KEY `cc` (`c`),
UNIQUE KEY `bb` (`b`(1)),
KEY `aa` (`a`)
) ENGINE=InnoDB COLLATE = utf8_general_ci
drop table t1;
create table t1(a int not null, key aa(a),
b char(10) not null, unique key bb(b(1)),
c char(4) not null);
desc t1;
Field Type Null Default Default_is_NULL On_Update
a INTEGER NO NO
b VARCHAR NO NO
c VARCHAR NO NO
alter table t1 add unique key cc(c);
desc t1;
Field Type Null Default Default_is_NULL On_Update
a INTEGER NO NO
b VARCHAR NO NO
c VARCHAR NO NO
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` INT NOT NULL,
`b` VARCHAR(10) COLLATE utf8_general_ci NOT NULL,
`c` VARCHAR(4) COLLATE utf8_general_ci NOT NULL,
UNIQUE KEY `cc` (`c`),
UNIQUE KEY `bb` (`b`(1)),
KEY `aa` (`a`)
) ENGINE=InnoDB COLLATE = utf8_general_ci
drop table t1;
End of 5.0 tests
DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (a INT PRIMARY KEY AUTO_INCREMENT);
INSERT INTO t1 VALUES (), (), ();
SELECT 1 AS c1
FROM t1
ORDER BY (
SELECT 1 AS c2
FROM t1
GROUP BY GREATEST(LAST_INSERT_ID(), t1.a) ASC
LIMIT 1);
c1
1
1
1
DROP TABLE t1;
CREATE TABLE t1 (a INT, b INT, INDEX (a,b));
INSERT INTO t1 (a, b)
VALUES
(1,1), (1,2), (1,3), (1,4), (1,5),
(2,2), (2,3), (2,1), (3,1), (4,1), (4,2), (4,3), (4,4), (4,5), (4,6);
EXPLAIN SELECT 1 FROM t1 AS t1_outer WHERE
(SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) > 12;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE
2 SUBQUERY t1 range NULL a 5 NULL 3 Using index for group-by
SELECT 1 as RES FROM t1 AS t1_outer WHERE
(SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) > 12;
RES
DROP TABLE t1;
|