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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700
|
drop table if exists t1,t2;
drop database if exists mysqltest;
create table t1 (
col1 int not null auto_increment primary key,
col2 varchar(30) not null,
col3 varchar (20) not null,
col4 varchar(4) not null,
col5 enum('PENDING', 'ACTIVE', 'DISABLED') not null,
col6 int not null, to_be_deleted int);
insert into t1 values (2,4,3,5,"PENDING",1,7);
alter table t1
add column col4_5 varchar(20) not null after col4,
add column col7 varchar(30) not null after col5,
add column col8 datetime not null, drop column to_be_deleted,
change column col2 fourth varchar(30) not null after col3,
modify column col6 int not null first;
select * from t1;
col6 col1 col3 fourth col4 col4_5 col5 col7 col8
1 2 3 4 5 PENDING 0000-00-00 00:00:00
drop table t1;
create table t1 (bandID MEDIUMINT UNSIGNED NOT NULL PRIMARY KEY, payoutID SMALLINT UNSIGNED NOT NULL);
insert into t1 (bandID,payoutID) VALUES (1,6),(2,6),(3,4),(4,9),(5,10),(6,1),(7,12),(8,12);
alter table t1 add column new_col int, order by payoutid,bandid;
select * from t1;
bandID payoutID new_col
6 1 NULL
3 4 NULL
1 6 NULL
2 6 NULL
4 9 NULL
5 10 NULL
7 12 NULL
8 12 NULL
alter table t1 order by bandid,payoutid;
select * from t1;
bandID payoutID new_col
1 6 NULL
2 6 NULL
3 4 NULL
4 9 NULL
5 10 NULL
6 1 NULL
7 12 NULL
8 12 NULL
drop table t1;
CREATE TABLE t1 (
GROUP_ID int(10) unsigned DEFAULT '0' NOT NULL,
LANG_ID smallint(5) unsigned DEFAULT '0' NOT NULL,
NAME varchar(80) DEFAULT '' NOT NULL,
PRIMARY KEY (GROUP_ID,LANG_ID),
KEY NAME (NAME));
ALTER TABLE t1 CHANGE NAME NAME CHAR(80) not null;
SHOW FULL COLUMNS FROM t1;
Field Type Collation Null Key Default Extra Privileges Comment
GROUP_ID int(10) unsigned NULL NO PRI 0 #
LANG_ID smallint(5) unsigned NULL NO PRI 0 #
NAME char(80) latin1_swedish_ci NO MUL #
DROP TABLE t1;
create table t1 (n int);
insert into t1 values(9),(3),(12),(10);
alter table t1 order by n;
select * from t1;
n
3
9
10
12
drop table t1;
CREATE TABLE t1 (
id int(11) unsigned NOT NULL default '0',
category_id tinyint(4) unsigned NOT NULL default '0',
type_id tinyint(4) unsigned NOT NULL default '0',
body text NOT NULL,
user_id int(11) unsigned NOT NULL default '0',
status enum('new','old') NOT NULL default 'new',
PRIMARY KEY (id)
) ENGINE=MyISAM;
ALTER TABLE t1 ORDER BY t1.id, t1.status, t1.type_id, t1.user_id, t1.body;
DROP TABLE t1;
CREATE TABLE t1 (AnamneseId int(10) unsigned NOT NULL auto_increment,B BLOB,PRIMARY KEY (AnamneseId)) engine=myisam;
insert into t1 values (null,"hello");
LOCK TABLES t1 WRITE;
ALTER TABLE t1 ADD Column new_col int not null;
UNLOCK TABLES;
OPTIMIZE TABLE t1;
Table Op Msg_type Msg_text
test.t1 optimize status OK
DROP TABLE t1;
create table t1 (i int unsigned not null auto_increment primary key);
insert into t1 values (null),(null),(null),(null);
alter table t1 drop i,add i int unsigned not null auto_increment, drop primary key, add primary key (i);
select * from t1;
i
1
2
3
4
drop table t1;
create table t1 (name char(15));
insert into t1 (name) values ("current");
create database mysqltest;
create table mysqltest.t1 (name char(15));
insert into mysqltest.t1 (name) values ("mysqltest");
select * from t1;
name
current
select * from mysqltest.t1;
name
mysqltest
alter table t1 rename mysqltest.t1;
ERROR 42S01: Table 't1' already exists
select * from t1;
name
current
select * from mysqltest.t1;
name
mysqltest
drop table t1;
drop database mysqltest;
create table t1 (n1 int not null, n2 int, n3 int, n4 float,
unique(n1),
key (n1, n2, n3, n4),
key (n2, n3, n4, n1),
key (n3, n4, n1, n2),
key (n4, n1, n2, n3) );
alter table t1 disable keys;
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 n1 1 n1 A 0 NULL NULL BTREE
t1 1 n1_2 1 n1 A NULL NULL NULL BTREE disabled
t1 1 n1_2 2 n2 A NULL NULL NULL YES BTREE disabled
t1 1 n1_2 3 n3 A NULL NULL NULL YES BTREE disabled
t1 1 n1_2 4 n4 A NULL NULL NULL YES BTREE disabled
t1 1 n2 1 n2 A NULL NULL NULL YES BTREE disabled
t1 1 n2 2 n3 A NULL NULL NULL YES BTREE disabled
t1 1 n2 3 n4 A NULL NULL NULL YES BTREE disabled
t1 1 n2 4 n1 A NULL NULL NULL BTREE disabled
t1 1 n3 1 n3 A NULL NULL NULL YES BTREE disabled
t1 1 n3 2 n4 A NULL NULL NULL YES BTREE disabled
t1 1 n3 3 n1 A NULL NULL NULL BTREE disabled
t1 1 n3 4 n2 A NULL NULL NULL YES BTREE disabled
t1 1 n4 1 n4 A NULL NULL NULL YES BTREE disabled
t1 1 n4 2 n1 A NULL NULL NULL BTREE disabled
t1 1 n4 3 n2 A NULL NULL NULL YES BTREE disabled
t1 1 n4 4 n3 A NULL NULL NULL YES BTREE disabled
insert into t1 values(10,RAND()*1000,RAND()*1000,RAND());
insert into t1 values(9,RAND()*1000,RAND()*1000,RAND());
insert into t1 values(8,RAND()*1000,RAND()*1000,RAND());
insert into t1 values(7,RAND()*1000,RAND()*1000,RAND());
insert into t1 values(6,RAND()*1000,RAND()*1000,RAND());
insert into t1 values(5,RAND()*1000,RAND()*1000,RAND());
insert into t1 values(4,RAND()*1000,RAND()*1000,RAND());
insert into t1 values(3,RAND()*1000,RAND()*1000,RAND());
insert into t1 values(2,RAND()*1000,RAND()*1000,RAND());
insert into t1 values(1,RAND()*1000,RAND()*1000,RAND());
alter table t1 enable keys;
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 n1 1 n1 A 10 NULL NULL BTREE
t1 1 n1_2 1 n1 A 10 NULL NULL BTREE
t1 1 n1_2 2 n2 A 10 NULL NULL YES BTREE
t1 1 n1_2 3 n3 A 10 NULL NULL YES BTREE
t1 1 n1_2 4 n4 A 10 NULL NULL YES BTREE
t1 1 n2 1 n2 A 10 NULL NULL YES BTREE
t1 1 n2 2 n3 A 10 NULL NULL YES BTREE
t1 1 n2 3 n4 A 10 NULL NULL YES BTREE
t1 1 n2 4 n1 A 10 NULL NULL BTREE
t1 1 n3 1 n3 A 10 NULL NULL YES BTREE
t1 1 n3 2 n4 A 10 NULL NULL YES BTREE
t1 1 n3 3 n1 A 10 NULL NULL BTREE
t1 1 n3 4 n2 A 10 NULL NULL YES BTREE
t1 1 n4 1 n4 A 10 NULL NULL YES BTREE
t1 1 n4 2 n1 A 10 NULL NULL BTREE
t1 1 n4 3 n2 A 10 NULL NULL YES BTREE
t1 1 n4 4 n3 A 10 NULL NULL YES BTREE
drop table t1;
create table t1 (i int unsigned not null auto_increment primary key);
alter table t1 rename t2;
alter table t2 rename t1, add c char(10) comment "no comment";
show columns from t1;
Field Type Null Key Default Extra
i int(10) unsigned NO PRI NULL auto_increment
c char(10) YES NULL
drop table t1;
create table t1 (a int, b int);
insert into t1 values(1,100), (2,100), (3, 100);
insert into t1 values(1,99), (2,99), (3, 99);
insert into t1 values(1,98), (2,98), (3, 98);
insert into t1 values(1,97), (2,97), (3, 97);
insert into t1 values(1,96), (2,96), (3, 96);
insert into t1 values(1,95), (2,95), (3, 95);
insert into t1 values(1,94), (2,94), (3, 94);
insert into t1 values(1,93), (2,93), (3, 93);
insert into t1 values(1,92), (2,92), (3, 92);
insert into t1 values(1,91), (2,91), (3, 91);
insert into t1 values(1,90), (2,90), (3, 90);
insert into t1 values(1,89), (2,89), (3, 89);
insert into t1 values(1,88), (2,88), (3, 88);
insert into t1 values(1,87), (2,87), (3, 87);
insert into t1 values(1,86), (2,86), (3, 86);
insert into t1 values(1,85), (2,85), (3, 85);
insert into t1 values(1,84), (2,84), (3, 84);
insert into t1 values(1,83), (2,83), (3, 83);
insert into t1 values(1,82), (2,82), (3, 82);
insert into t1 values(1,81), (2,81), (3, 81);
insert into t1 values(1,80), (2,80), (3, 80);
insert into t1 values(1,79), (2,79), (3, 79);
insert into t1 values(1,78), (2,78), (3, 78);
insert into t1 values(1,77), (2,77), (3, 77);
insert into t1 values(1,76), (2,76), (3, 76);
insert into t1 values(1,75), (2,75), (3, 75);
insert into t1 values(1,74), (2,74), (3, 74);
insert into t1 values(1,73), (2,73), (3, 73);
insert into t1 values(1,72), (2,72), (3, 72);
insert into t1 values(1,71), (2,71), (3, 71);
insert into t1 values(1,70), (2,70), (3, 70);
insert into t1 values(1,69), (2,69), (3, 69);
insert into t1 values(1,68), (2,68), (3, 68);
insert into t1 values(1,67), (2,67), (3, 67);
insert into t1 values(1,66), (2,66), (3, 66);
insert into t1 values(1,65), (2,65), (3, 65);
insert into t1 values(1,64), (2,64), (3, 64);
insert into t1 values(1,63), (2,63), (3, 63);
insert into t1 values(1,62), (2,62), (3, 62);
insert into t1 values(1,61), (2,61), (3, 61);
insert into t1 values(1,60), (2,60), (3, 60);
insert into t1 values(1,59), (2,59), (3, 59);
insert into t1 values(1,58), (2,58), (3, 58);
insert into t1 values(1,57), (2,57), (3, 57);
insert into t1 values(1,56), (2,56), (3, 56);
insert into t1 values(1,55), (2,55), (3, 55);
insert into t1 values(1,54), (2,54), (3, 54);
insert into t1 values(1,53), (2,53), (3, 53);
insert into t1 values(1,52), (2,52), (3, 52);
insert into t1 values(1,51), (2,51), (3, 51);
insert into t1 values(1,50), (2,50), (3, 50);
insert into t1 values(1,49), (2,49), (3, 49);
insert into t1 values(1,48), (2,48), (3, 48);
insert into t1 values(1,47), (2,47), (3, 47);
insert into t1 values(1,46), (2,46), (3, 46);
insert into t1 values(1,45), (2,45), (3, 45);
insert into t1 values(1,44), (2,44), (3, 44);
insert into t1 values(1,43), (2,43), (3, 43);
insert into t1 values(1,42), (2,42), (3, 42);
insert into t1 values(1,41), (2,41), (3, 41);
insert into t1 values(1,40), (2,40), (3, 40);
insert into t1 values(1,39), (2,39), (3, 39);
insert into t1 values(1,38), (2,38), (3, 38);
insert into t1 values(1,37), (2,37), (3, 37);
insert into t1 values(1,36), (2,36), (3, 36);
insert into t1 values(1,35), (2,35), (3, 35);
insert into t1 values(1,34), (2,34), (3, 34);
insert into t1 values(1,33), (2,33), (3, 33);
insert into t1 values(1,32), (2,32), (3, 32);
insert into t1 values(1,31), (2,31), (3, 31);
insert into t1 values(1,30), (2,30), (3, 30);
insert into t1 values(1,29), (2,29), (3, 29);
insert into t1 values(1,28), (2,28), (3, 28);
insert into t1 values(1,27), (2,27), (3, 27);
insert into t1 values(1,26), (2,26), (3, 26);
insert into t1 values(1,25), (2,25), (3, 25);
insert into t1 values(1,24), (2,24), (3, 24);
insert into t1 values(1,23), (2,23), (3, 23);
insert into t1 values(1,22), (2,22), (3, 22);
insert into t1 values(1,21), (2,21), (3, 21);
insert into t1 values(1,20), (2,20), (3, 20);
insert into t1 values(1,19), (2,19), (3, 19);
insert into t1 values(1,18), (2,18), (3, 18);
insert into t1 values(1,17), (2,17), (3, 17);
insert into t1 values(1,16), (2,16), (3, 16);
insert into t1 values(1,15), (2,15), (3, 15);
insert into t1 values(1,14), (2,14), (3, 14);
insert into t1 values(1,13), (2,13), (3, 13);
insert into t1 values(1,12), (2,12), (3, 12);
insert into t1 values(1,11), (2,11), (3, 11);
insert into t1 values(1,10), (2,10), (3, 10);
insert into t1 values(1,9), (2,9), (3, 9);
insert into t1 values(1,8), (2,8), (3, 8);
insert into t1 values(1,7), (2,7), (3, 7);
insert into t1 values(1,6), (2,6), (3, 6);
insert into t1 values(1,5), (2,5), (3, 5);
insert into t1 values(1,4), (2,4), (3, 4);
insert into t1 values(1,3), (2,3), (3, 3);
insert into t1 values(1,2), (2,2), (3, 2);
insert into t1 values(1,1), (2,1), (3, 1);
alter table t1 add unique (a,b), add key (b);
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 a 1 a A NULL NULL NULL YES BTREE
t1 0 a 2 b A NULL NULL NULL YES BTREE
t1 1 b 1 b A 100 NULL NULL YES BTREE
analyze table t1;
Table Op Msg_type Msg_text
test.t1 analyze status OK
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 a 1 a A 3 NULL NULL YES BTREE
t1 0 a 2 b A 300 NULL NULL YES BTREE
t1 1 b 1 b A 100 NULL NULL YES BTREE
drop table t1;
CREATE TABLE t1 (i int(10), index(i) );
ALTER TABLE t1 DISABLE KEYS;
INSERT DELAYED INTO t1 VALUES(1),(2),(3);
ALTER TABLE t1 ENABLE KEYS;
drop table t1;
CREATE TABLE t1 (
Host varchar(16) binary NOT NULL default '',
User varchar(16) binary NOT NULL default '',
PRIMARY KEY (Host,User)
) ENGINE=MyISAM;
ALTER TABLE t1 DISABLE KEYS;
LOCK TABLES t1 WRITE;
INSERT INTO t1 VALUES ('localhost','root'),('localhost',''),('games','monty');
SHOW INDEX 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 Host A NULL NULL NULL BTREE
t1 0 PRIMARY 2 User A 0 NULL NULL BTREE
ALTER TABLE t1 ENABLE KEYS;
UNLOCK TABLES;
CHECK TABLES t1;
Table Op Msg_type Msg_text
test.t1 check status OK
DROP TABLE t1;
CREATE TABLE t1 (
Host varchar(16) binary NOT NULL default '',
User varchar(16) binary NOT NULL default '',
PRIMARY KEY (Host,User),
KEY (Host)
) ENGINE=MyISAM;
ALTER TABLE t1 DISABLE KEYS;
SHOW INDEX 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 Host A NULL NULL NULL BTREE
t1 0 PRIMARY 2 User A 0 NULL NULL BTREE
t1 1 Host 1 Host A NULL NULL NULL BTREE disabled
LOCK TABLES t1 WRITE;
INSERT INTO t1 VALUES ('localhost','root'),('localhost','');
SHOW INDEX 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 Host A NULL NULL NULL BTREE
t1 0 PRIMARY 2 User A 0 NULL NULL BTREE
t1 1 Host 1 Host A NULL NULL NULL BTREE disabled
ALTER TABLE t1 ENABLE KEYS;
SHOW INDEX 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 Host A NULL NULL NULL BTREE
t1 0 PRIMARY 2 User A 2 NULL NULL BTREE
t1 1 Host 1 Host A 1 NULL NULL BTREE
UNLOCK TABLES;
CHECK TABLES t1;
Table Op Msg_type Msg_text
test.t1 check status OK
LOCK TABLES t1 WRITE;
ALTER TABLE t1 RENAME t2;
UNLOCK TABLES;
select * from t2;
Host User
localhost
localhost root
DROP TABLE t2;
CREATE TABLE t1 (
Host varchar(16) binary NOT NULL default '',
User varchar(16) binary NOT NULL default '',
PRIMARY KEY (Host,User),
KEY (Host)
) ENGINE=MyISAM;
LOCK TABLES t1 WRITE;
ALTER TABLE t1 DISABLE KEYS;
SHOW INDEX 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 Host A NULL NULL NULL BTREE
t1 0 PRIMARY 2 User A 0 NULL NULL BTREE
t1 1 Host 1 Host A NULL NULL NULL BTREE disabled
DROP TABLE t1;
create table t1 (a int);
alter table t1 rename to `t1\\`;
ERROR 42000: Incorrect table name 't1\\'
rename table t1 to `t1\\`;
ERROR 42000: Incorrect table name 't1\\'
drop table t1;
drop table if exists t1, t2;
Warnings:
Note 1051 Unknown table 't1'
Note 1051 Unknown table 't2'
create table t1 ( a varchar(10) not null primary key ) engine=myisam;
create table t2 ( a varchar(10) not null primary key ) engine=merge union=(t1);
flush tables;
alter table t1 modify a varchar(10);
show create table t2;
Table Create Table
t2 CREATE TABLE `t2` (
`a` varchar(10) NOT NULL,
PRIMARY KEY (`a`)
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t1`)
flush tables;
alter table t1 modify a varchar(10) not null;
show create table t2;
Table Create Table
t2 CREATE TABLE `t2` (
`a` varchar(10) NOT NULL,
PRIMARY KEY (`a`)
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t1`)
drop table if exists t1, t2;
create table t1 (a int, b int, c int, d int, e int, f int, g int, h int,i int, primary key (a,b,c,d,e,f,g,i,h)) engine=MyISAM;
insert into t1 (a) values(1);
show table status like 't1';
Name Engine Version Row_format Rows Avg_row_length Data_length Max_data_length Index_length Data_free Auto_increment Create_time Update_time Check_time Collation Checksum Create_options Comment
t1 MyISAM 10 Fixed 1 37 X X X X X X X X latin1_swedish_ci NULL
alter table t1 modify a int;
show table status like 't1';
Name Engine Version Row_format Rows Avg_row_length Data_length Max_data_length Index_length Data_free Auto_increment Create_time Update_time Check_time Collation Checksum Create_options Comment
t1 MyISAM 10 Fixed 1 37 X X X X X X X X latin1_swedish_ci NULL
drop table t1;
create table t1 (a int not null, b int not null, c int not null, d int not null, e int not null, f int not null, g int not null, h int not null,i int not null, primary key (a,b,c,d,e,f,g,i,h)) engine=MyISAM;
insert into t1 (a) values(1);
Warnings:
Warning 1364 Field 'b' doesn't have a default value
Warning 1364 Field 'c' doesn't have a default value
Warning 1364 Field 'd' doesn't have a default value
Warning 1364 Field 'e' doesn't have a default value
Warning 1364 Field 'f' doesn't have a default value
Warning 1364 Field 'g' doesn't have a default value
Warning 1364 Field 'h' doesn't have a default value
Warning 1364 Field 'i' doesn't have a default value
show table status like 't1';
Name Engine Version Row_format Rows Avg_row_length Data_length Max_data_length Index_length Data_free Auto_increment Create_time Update_time Check_time Collation Checksum Create_options Comment
t1 MyISAM 10 Fixed 1 37 X X X X X X X X latin1_swedish_ci NULL
drop table t1;
set names koi8r;
create table t1 (a char(10) character set koi8r);
insert into t1 values ('');
select a,hex(a) from t1;
a hex(a)
D4C5D3D4
alter table t1 change a a char(10) character set cp1251;
select a,hex(a) from t1;
a hex(a)
F2E5F1F2
alter table t1 change a a binary(4);
select a,hex(a) from t1;
a hex(a)
F2E5F1F2
alter table t1 change a a char(10) character set cp1251;
select a,hex(a) from t1;
a hex(a)
F2E5F1F2
alter table t1 change a a char(10) character set koi8r;
select a,hex(a) from t1;
a hex(a)
D4C5D3D4
alter table t1 change a a varchar(10) character set cp1251;
select a,hex(a) from t1;
a hex(a)
F2E5F1F2
alter table t1 change a a char(10) character set koi8r;
select a,hex(a) from t1;
a hex(a)
D4C5D3D4
alter table t1 change a a text character set cp1251;
select a,hex(a) from t1;
a hex(a)
F2E5F1F2
alter table t1 change a a char(10) character set koi8r;
select a,hex(a) from t1;
a hex(a)
D4C5D3D4
delete from t1;
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` char(10) character set koi8r default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
alter table t1 DEFAULT CHARACTER SET latin1;
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` char(10) character set koi8r default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
alter table t1 CONVERT TO CHARACTER SET latin1;
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` char(10) default NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1
alter table t1 DEFAULT CHARACTER SET cp1251;
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` char(10) character set latin1 default NULL
) ENGINE=MyISAM DEFAULT CHARSET=cp1251
drop table t1;
create table t1 (myblob longblob,mytext longtext)
default charset latin1 collate latin1_general_cs;
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`myblob` longblob,
`mytext` longtext collate latin1_general_cs
) ENGINE=MyISAM DEFAULT CHARSET=latin1 COLLATE=latin1_general_cs
alter table t1 character set latin2;
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`myblob` longblob,
`mytext` longtext character set latin1 collate latin1_general_cs
) ENGINE=MyISAM DEFAULT CHARSET=latin2
drop table t1;
CREATE TABLE t1 (a int PRIMARY KEY, b INT UNIQUE);
ALTER TABLE t1 DROP PRIMARY KEY;
SHOW CREATE TABLE t1;
Table Create Table
t1 CREATE TABLE `t1` (
`a` int(11) NOT NULL,
`b` int(11) default NULL,
UNIQUE KEY `b` (`b`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1
ALTER TABLE t1 DROP PRIMARY KEY;
ERROR 42000: Can't DROP 'PRIMARY'; check that column/key exists
DROP TABLE t1;
create table t1 (a int, b int, key(a));
insert into t1 values (1,1), (2,2);
alter table t1 drop key no_such_key;
ERROR 42000: Can't DROP 'no_such_key'; check that column/key exists
alter table t1 drop key a;
drop table t1;
CREATE TABLE T12207(a int) ENGINE=MYISAM;
ALTER TABLE T12207 DISCARD TABLESPACE;
ERROR HY000: Table storage engine for 'T12207' doesn't have this option
DROP TABLE T12207;
create table t1 (a text) character set koi8r;
insert into t1 values (_koi8r'');
select hex(a) from t1;
hex(a)
D4C5D3D4
alter table t1 convert to character set cp1251;
select hex(a) from t1;
hex(a)
F2E5F1F2
drop table t1;
create table t1 ( a timestamp );
alter table t1 add unique ( a(1) );
ERROR HY000: Incorrect sub part key; the used key part isn't a string, the used length is longer than the key part, or the storage engine doesn't support unique sub keys
drop table t1;
drop table if exists t1;
create table t1 (a int, key(a));
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 1 a 1 a A NULL NULL NULL YES BTREE
"this used not to disable the index"
alter table t1 modify a int, disable keys;
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 1 a 1 a A NULL NULL NULL YES BTREE disabled
alter table t1 enable keys;
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 1 a 1 a A NULL NULL NULL YES BTREE
alter table t1 modify a bigint, disable keys;
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 1 a 1 a A NULL NULL NULL YES BTREE disabled
alter table t1 enable keys;
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 1 a 1 a A NULL NULL NULL YES BTREE
alter table t1 add b char(10), disable keys;
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 1 a 1 a A NULL NULL NULL YES BTREE disabled
alter table t1 add c decimal(10,2), enable keys;
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 1 a 1 a A NULL NULL NULL YES BTREE
"this however did"
alter table t1 disable keys;
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 1 a 1 a A NULL NULL NULL YES BTREE disabled
desc t1;
Field Type Null Key Default Extra
a bigint(20) YES MUL NULL
b char(10) YES NULL
c decimal(10,2) YES NULL
alter table t1 add d decimal(15,5);
"The key should still be disabled"
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 1 a 1 a A NULL NULL NULL YES BTREE disabled
drop table t1;
"Now will test with one unique index"
create table t1(a int, b char(10), unique(a));
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 0 a 1 a A NULL NULL NULL YES BTREE
alter table t1 disable keys;
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 0 a 1 a A NULL NULL NULL YES BTREE
alter table t1 enable keys;
"If no copy on noop change, this won't touch the data file"
"Unique index, no change"
alter table t1 modify a int, disable keys;
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 0 a 1 a A NULL NULL NULL YES BTREE
"Change the type implying data copy"
"Unique index, no change"
alter table t1 modify a bigint, disable keys;
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 0 a 1 a A NULL NULL NULL YES BTREE
alter table t1 modify a bigint;
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 0 a 1 a A NULL NULL NULL YES BTREE
alter table t1 modify a int;
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 0 a 1 a A NULL NULL NULL YES BTREE
drop table t1;
"Now will test with one unique and one non-unique index"
create table t1(a int, b char(10), unique(a), key(b));
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 0 a 1 a A NULL NULL NULL YES BTREE
t1 1 b 1 b A NULL NULL NULL YES BTREE
alter table t1 disable keys;
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 0 a 1 a A NULL NULL NULL YES BTREE
t1 1 b 1 b A NULL NULL NULL YES BTREE disabled
alter table t1 enable keys;
"If no copy on noop change, this won't touch the data file"
"The non-unique index will be disabled"
alter table t1 modify a int, disable keys;
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 0 a 1 a A NULL NULL NULL YES BTREE
t1 1 b 1 b A NULL NULL NULL YES BTREE disabled
alter table t1 enable keys;
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 0 a 1 a A NULL NULL NULL YES BTREE
t1 1 b 1 b A NULL NULL NULL YES BTREE
"Change the type implying data copy"
"The non-unique index will be disabled"
alter table t1 modify a bigint, disable keys;
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 0 a 1 a A NULL NULL NULL YES BTREE
t1 1 b 1 b A NULL NULL NULL YES BTREE disabled
"Change again the type, but leave the indexes as_is"
alter table t1 modify a int;
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 0 a 1 a A NULL NULL NULL YES BTREE
t1 1 b 1 b A NULL NULL NULL YES BTREE disabled
"Try the same. When data is no copied on similar tables, this is noop"
alter table t1 modify a int;
show indexes from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
t1 0 a 1 a A NULL NULL NULL YES BTREE
t1 1 b 1 b A NULL NULL NULL YES BTREE disabled
drop table t1;
create database mysqltest;
create table t1 (c1 int);
alter table t1 rename mysqltest.t1;
drop table t1;
ERROR 42S02: Unknown table 't1'
alter table mysqltest.t1 rename t1;
drop table t1;
create table t1 (c1 int);
use mysqltest;
drop database mysqltest;
alter table test.t1 rename t1;
ERROR 3D000: No database selected
alter table test.t1 rename test.t1;
use test;
drop table t1;
DROP TABLE IF EXISTS bug24219;
DROP TABLE IF EXISTS bug24219_2;
CREATE TABLE bug24219 (a INT, INDEX(a));
SHOW INDEX FROM bug24219;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
bug24219 1 a 1 a A NULL NULL NULL YES BTREE
ALTER TABLE bug24219 RENAME TO bug24219_2, DISABLE KEYS;
SHOW INDEX FROM bug24219_2;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment
bug24219_2 1 a 1 a A NULL NULL NULL YES BTREE disabled
DROP TABLE bug24219_2;
create table t1 (mycol int(10) not null);
alter table t1 alter column mycol set default 0;
desc t1;
Field Type Null Key Default Extra
mycol int(10) NO 0
drop table t1;
create table t1 (t varchar(255) default null, key t (t(80)))
engine=myisam default charset=latin1;
alter table t1 change t t text;
drop table t1;
|