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
|
CREATE TABLE parent (a INT PRIMARY KEY, b INT NOT NULL) ENGINE = InnoDB;
INSERT INTO parent VALUES(1,2),(2,3);
CREATE INDEX tb ON parent(b);
INSERT INTO parent VALUES(10,20),(20,30);
CREATE TABLE child (a1 INT PRIMARY KEY, a2 INT) ENGINE = InnoDB;
CREATE INDEX tb ON child(a2);
INSERT INTO child VALUES(10,20);
ALTER TABLE child ADD FOREIGN KEY(a2) REFERENCES parent(b),
ALGORITHM = INPLACE;
ERROR 0A000: ALGORITHM=INPLACE is not supported. Reason: Adding foreign keys needs foreign_key_checks=OFF. Try ALGORITHM=COPY
SET foreign_key_checks = 0;
ALTER TABLE child ADD CONSTRAINT fk_1 FOREIGN KEY (a2)
REFERENCES parent(b) ON DELETE SET NULL ON UPDATE CASCADE,
ALGORITHM = INPLACE;
SELECT * FROM information_schema.INNODB_SYS_FOREIGN;
ID FOR_NAME REF_NAME N_COLS TYPE
test/fk_1 test/child test/parent 1 6
SELECT * FROM information_schema.INNODB_SYS_FOREIGN_COLS;
ID FOR_COL_NAME REF_COL_NAME POS
test/fk_1 a2 b 0
ALTER TABLE child ADD CONSTRAINT fk_1 FOREIGN KEY (a2)
REFERENCES parent(b) ON DELETE SET NULL ON UPDATE CASCADE,
ALGORITHM = INPLACE;
ERROR HY000: Duplicate FOREIGN KEY constraint name 'test/fk_1'
SET foreign_key_checks = 1;
INSERT INTO child VALUES(1,2),(2,3);
INSERT INTO child VALUES(4,4);
ERROR 23000: Cannot add or update a child row: a foreign key constraint fails (`test`.`child`, CONSTRAINT `fk_1` FOREIGN KEY (`a2`) REFERENCES `parent` (`b`) ON DELETE SET NULL ON UPDATE CASCADE)
SELECT * FROM parent;
a b
1 2
2 3
10 20
20 30
SET foreign_key_checks = 0;
ALTER TABLE child ADD CONSTRAINT fk_20 FOREIGN KEY (a1, a2)
REFERENCES parent(a, b) ON DELETE CASCADE ON UPDATE CASCADE,
ALGORITHM = INPLACE;
ERROR HY000: Failed to add the foreign key constraint. Missing index for constraint 'fk_20' in the referenced table 'parent'
SHOW WARNINGS;
Level Code Message
Error 1822 Failed to add the foreign key constraint. Missing index for constraint 'fk_20' in the referenced table 'parent'
SHOW ERRORS;
Level Code Message
Error 1822 Failed to add the foreign key constraint. Missing index for constraint 'fk_20' in the referenced table 'parent'
CREATE INDEX idx1 on parent(a, b);
ALTER TABLE child ADD CONSTRAINT fk_10 FOREIGN KEY (a1, a2)
REFERENCES parent(a, b) ON DELETE CASCADE ON UPDATE CASCADE,
ALGORITHM = INPLACE;
ALTER TABLE child ADD CONSTRAINT fk_2 FOREIGN KEY (a1, a2)
REFERENCES parent(a, b) ON DELETE CASCADE ON UPDATE CASCADE, ADD INDEX idx1(a1,a2),
ALGORITHM = INPLACE;
ALTER TABLE child ADD CONSTRAINT fk_3 FOREIGN KEY (a1, a2)
REFERENCES parent(a, b) ON DELETE CASCADE ON UPDATE CASCADE;
SELECT * FROM information_schema.INNODB_SYS_FOREIGN;
ID FOR_NAME REF_NAME N_COLS TYPE
test/fk_1 test/child test/parent 1 6
test/fk_10 test/child test/parent 2 5
test/fk_2 test/child test/parent 2 5
test/fk_3 test/child test/parent 2 5
SELECT * FROM information_schema.INNODB_SYS_FOREIGN_COLS;
ID FOR_COL_NAME REF_COL_NAME POS
test/fk_1 a2 b 0
test/fk_10 a1 a 0
test/fk_10 a2 b 1
test/fk_2 a1 a 0
test/fk_2 a2 b 1
test/fk_3 a1 a 0
test/fk_3 a2 b 1
SET foreign_key_checks = 1;
INSERT INTO child VALUES(5,4);
ERROR 23000: Cannot add or update a child row: a foreign key constraint fails (`test`.`child`, CONSTRAINT `fk_1` FOREIGN KEY (`a2`) REFERENCES `parent` (`b`) ON DELETE SET NULL ON UPDATE CASCADE)
SHOW CREATE TABLE child;
Table Create Table
child CREATE TABLE `child` (
`a1` int(11) NOT NULL,
`a2` int(11) DEFAULT NULL,
PRIMARY KEY (`a1`),
KEY `tb` (`a2`),
KEY `idx1` (`a1`,`a2`),
CONSTRAINT `fk_1` FOREIGN KEY (`a2`) REFERENCES `parent` (`b`) ON DELETE SET NULL ON UPDATE CASCADE,
CONSTRAINT `fk_10` FOREIGN KEY (`a1`, `a2`) REFERENCES `parent` (`a`, `b`) ON DELETE CASCADE ON UPDATE CASCADE,
CONSTRAINT `fk_2` FOREIGN KEY (`a1`, `a2`) REFERENCES `parent` (`a`, `b`) ON DELETE CASCADE ON UPDATE CASCADE,
CONSTRAINT `fk_3` FOREIGN KEY (`a1`, `a2`) REFERENCES `parent` (`a`, `b`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DELETE FROM parent where a = 1;
SELECT * FROM child;
a1 a2
1 NULL
2 3
10 20
SET foreign_key_checks = 0;
SET @saved_debug_dbug = @@SESSION.debug_dbug;
SET DEBUG_DBUG = '+d,innodb_test_open_ref_fail';
ALTER TABLE child ADD CONSTRAINT fk_4 FOREIGN KEY (a1, a2)
REFERENCES parent(a, b) ON DELETE CASCADE ON UPDATE CASCADE,
ALGORITHM = INPLACE;
SET DEBUG_DBUG = @saved_debug_dbug;
SELECT * FROM information_schema.INNODB_SYS_FOREIGN;
ID FOR_NAME REF_NAME N_COLS TYPE
test/fk_1 test/child test/parent 1 6
test/fk_10 test/child test/parent 2 5
test/fk_2 test/child test/parent 2 5
test/fk_3 test/child test/parent 2 5
test/fk_4 test/child test/parent 2 5
SELECT * FROM information_schema.INNODB_SYS_FOREIGN_COLS;
ID FOR_COL_NAME REF_COL_NAME POS
test/fk_1 a2 b 0
test/fk_10 a1 a 0
test/fk_10 a2 b 1
test/fk_2 a1 a 0
test/fk_2 a2 b 1
test/fk_3 a1 a 0
test/fk_3 a2 b 1
test/fk_4 a1 a 0
test/fk_4 a2 b 1
SELECT t2.name, t1.name FROM information_schema.innodb_sys_columns t1, information_schema.innodb_sys_tables t2 WHERE t1.table_id = t2.table_id AND t2.name LIKE "%child" ORDER BY t1.name;
name name
test/child a1
test/child a2
SELECT NAME FROM information_schema.INNODB_SYS_TABLES;
NAME
SYS_FOREIGN
SYS_FOREIGN_COLS
SYS_VIRTUAL
mysql/innodb_index_stats
mysql/innodb_table_stats
mysql/transaction_registry
test/child
test/parent
INSERT INTO child VALUES(5,4);
SET foreign_key_checks = 1;
INSERT INTO child VALUES(6,5);
ERROR 23000: Cannot add or update a child row: a foreign key constraint fails (`test`.`child`, CONSTRAINT `fk_1` FOREIGN KEY (`a2`) REFERENCES `parent` (`b`) ON DELETE SET NULL ON UPDATE CASCADE)
SET foreign_key_checks = 0;
CREATE TABLE `#parent` (a INT PRIMARY KEY, b INT NOT NULL) ENGINE = InnoDB;
CREATE INDEX tb ON `#parent`(a, b);
CREATE TABLE `#child` (a1 INT PRIMARY KEY, a2 INT) ENGINE = InnoDB;
CREATE INDEX tb ON `#child`(a1, a2);
SET DEBUG_DBUG = '+d,innodb_test_no_foreign_idx';
ALTER TABLE `#child` ADD CONSTRAINT fk_40 FOREIGN KEY (a1, a2)
REFERENCES `#parent`(a, b) ON DELETE CASCADE ON UPDATE CASCADE,
ALGORITHM = INPLACE;
ERROR HY000: Failed to add the foreign key constraint. Missing index for constraint 'fk_40' in the foreign table '#child'
SET DEBUG_DBUG = @saved_debug_dbug;
SHOW ERRORS;
Level Code Message
Error 1821 Failed to add the foreign key constraint. Missing index for constraint 'fk_40' in the foreign table '#child'
SELECT * FROM information_schema.INNODB_SYS_FOREIGN;
ID FOR_NAME REF_NAME N_COLS TYPE
test/fk_1 test/child test/parent 1 6
test/fk_10 test/child test/parent 2 5
test/fk_2 test/child test/parent 2 5
test/fk_3 test/child test/parent 2 5
test/fk_4 test/child test/parent 2 5
SELECT * FROM information_schema.INNODB_SYS_FOREIGN_COLS;
ID FOR_COL_NAME REF_COL_NAME POS
test/fk_1 a2 b 0
test/fk_10 a1 a 0
test/fk_10 a2 b 1
test/fk_2 a1 a 0
test/fk_2 a2 b 1
test/fk_3 a1 a 0
test/fk_3 a2 b 1
test/fk_4 a1 a 0
test/fk_4 a2 b 1
SET DEBUG_DBUG = '+d,innodb_test_no_reference_idx';
ALTER TABLE child ADD CONSTRAINT fk_42 FOREIGN KEY (a1, a2)
REFERENCES parent(a, b) ON DELETE CASCADE ON UPDATE CASCADE,
ALGORITHM = INPLACE;
ERROR HY000: Failed to add the foreign key constraint. Missing index for constraint 'fk_42' in the referenced table 'parent'
SET DEBUG_DBUG = @saved_debug_dbug;
SHOW ERRORS;
Level Code Message
Error 1822 Failed to add the foreign key constraint. Missing index for constraint 'fk_42' in the referenced table 'parent'
SET DEBUG_DBUG = '+d,innodb_test_wrong_fk_option';
ALTER TABLE child ADD CONSTRAINT fk_42 FOREIGN KEY (a1, a2)
REFERENCES parent(a, b) ON DELETE CASCADE ON UPDATE CASCADE,
ALGORITHM = INPLACE;
ERROR HY000: Failed to add the foreign key constraint on table 'child'. Incorrect options in FOREIGN KEY constraint 'test/fk_42'
SET DEBUG_DBUG = @saved_debug_dbug;
SELECT * FROM information_schema.INNODB_SYS_FOREIGN;
ID FOR_NAME REF_NAME N_COLS TYPE
test/fk_1 test/child test/parent 1 6
test/fk_10 test/child test/parent 2 5
test/fk_2 test/child test/parent 2 5
test/fk_3 test/child test/parent 2 5
test/fk_4 test/child test/parent 2 5
SELECT * FROM information_schema.INNODB_SYS_FOREIGN_COLS;
ID FOR_COL_NAME REF_COL_NAME POS
test/fk_1 a2 b 0
test/fk_10 a1 a 0
test/fk_10 a2 b 1
test/fk_2 a1 a 0
test/fk_2 a2 b 1
test/fk_3 a1 a 0
test/fk_3 a2 b 1
test/fk_4 a1 a 0
test/fk_4 a2 b 1
SET DEBUG_DBUG = '+d,innodb_test_cannot_add_fk_system';
ALTER TABLE `#child` ADD CONSTRAINT fk_43 FOREIGN KEY (a1, a2)
REFERENCES `#parent`(a, b) ON DELETE CASCADE ON UPDATE CASCADE,
ALGORITHM = INPLACE;
ERROR HY000: Failed to add the foreign key constraint 'test/fk_43' to system tables
SET DEBUG_DBUG = @saved_debug_dbug;
SHOW ERRORS;
Level Code Message
Error 1823 Failed to add the foreign key constraint 'test/fk_43' to system tables
DROP TABLE `#child`;
DROP TABLE `#parent`;
SET foreign_key_checks = 0;
ALTER TABLE child ADD CONSTRAINT fk_5 FOREIGN KEY (a2) REFERENCES parent(b)
ON DELETE SET NULL ON UPDATE CASCADE,
ADD CONSTRAINT fk_6 FOREIGN KEY (a1, a2)
REFERENCES parent(a, b) ON DELETE CASCADE ON UPDATE CASCADE,
ALGORITHM = INPLACE;
SELECT * FROM information_schema.INNODB_SYS_FOREIGN;
ID FOR_NAME REF_NAME N_COLS TYPE
test/fk_1 test/child test/parent 1 6
test/fk_10 test/child test/parent 2 5
test/fk_2 test/child test/parent 2 5
test/fk_3 test/child test/parent 2 5
test/fk_4 test/child test/parent 2 5
test/fk_5 test/child test/parent 1 6
test/fk_6 test/child test/parent 2 5
SELECT * FROM information_schema.INNODB_SYS_FOREIGN_COLS;
ID FOR_COL_NAME REF_COL_NAME POS
test/fk_1 a2 b 0
test/fk_10 a1 a 0
test/fk_10 a2 b 1
test/fk_2 a1 a 0
test/fk_2 a2 b 1
test/fk_3 a1 a 0
test/fk_3 a2 b 1
test/fk_4 a1 a 0
test/fk_4 a2 b 1
test/fk_5 a2 b 0
test/fk_6 a1 a 0
test/fk_6 a2 b 1
DROP TABLE child;
DROP TABLE parent;
CREATE TABLE parent (a INT PRIMARY KEY, b INT NOT NULL) ENGINE = InnoDB;
INSERT INTO parent VALUES(1,2),(2,3);
CREATE INDEX tb ON parent(b);
INSERT INTO parent VALUES(10,20),(20,30);
CREATE TABLE child (a1 INT PRIMARY KEY, a2 INT) ENGINE = InnoDB;
CREATE INDEX tb ON child(a2);
INSERT INTO child VALUES(10,20);
SET foreign_key_checks = 0;
ALTER TABLE child DROP INDEX tb, ADD CONSTRAINT fk_4 FOREIGN KEY (a2)
REFERENCES parent(b) ON DELETE CASCADE ON UPDATE CASCADE,
ALGORITHM = INPLACE;
SHOW CREATE TABLE child;
Table Create Table
child CREATE TABLE `child` (
`a1` int(11) NOT NULL,
`a2` int(11) DEFAULT NULL,
PRIMARY KEY (`a1`),
KEY `fk_4` (`a2`),
CONSTRAINT `fk_4` FOREIGN KEY (`a2`) REFERENCES `parent` (`b`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
SELECT * FROM information_schema.INNODB_SYS_FOREIGN;
ID FOR_NAME REF_NAME N_COLS TYPE
test/fk_4 test/child test/parent 1 5
SELECT * FROM information_schema.INNODB_SYS_FOREIGN_COLS;
ID FOR_COL_NAME REF_COL_NAME POS
test/fk_4 a2 b 0
SET foreign_key_checks = 1;
DROP TABLE child;
DROP TABLE parent;
CREATE TABLE parent (a INT PRIMARY KEY, b INT NOT NULL) ENGINE = InnoDB;
INSERT INTO parent VALUES(1,2),(2,3);
CREATE INDEX tb ON parent(b);
INSERT INTO parent VALUES(10,20),(20,30);
CREATE TABLE child (a1 INT PRIMARY KEY, a2 INT) ENGINE = InnoDB;
CREATE INDEX tb ON child(a2);
SET foreign_key_checks = 0;
ALTER TABLE child CHANGE a2 a3 INT,
ADD CONSTRAINT fk_1 FOREIGN KEY (a2) REFERENCES parent(b)
ON DELETE SET NULL ON UPDATE CASCADE,
ALGORITHM = INPLACE;
ERROR 42000: Key column 'a2' doesn't exist in table
ALTER TABLE child CHANGE a2 a3 INT,
ADD CONSTRAINT fk_1 FOREIGN KEY (a3) REFERENCES parent(b)
ON DELETE SET NULL ON UPDATE CASCADE,
ALGORITHM = INPLACE;
DROP TABLE child;
DROP TABLE parent;
CREATE TABLE parent (a INT PRIMARY KEY, b INT NOT NULL) ENGINE = InnoDB;
INSERT INTO parent VALUES(1,2),(2,3);
CREATE INDEX tb ON parent(b);
INSERT INTO parent VALUES(10,20),(20,30);
CREATE TABLE child (a1 INT NOT NULL, a2 INT) ENGINE = InnoDB;
CREATE INDEX tb ON child(a2);
SET foreign_key_checks = 0;
SET DEBUG_DBUG = '+d,innodb_test_cannot_add_fk_system';
ALTER TABLE child ADD PRIMARY KEY idx (a3), CHANGE a1 a3 INT,
ADD CONSTRAINT fk_1 FOREIGN KEY (a2) REFERENCES parent(b)
ON DELETE SET NULL ON UPDATE CASCADE,
ALGORITHM = INPLACE;
ERROR HY000: Failed to add the foreign key constraint 'test/fk_1' to system tables
SET DEBUG_DBUG = @saved_debug_dbug;
SELECT * FROM INFORMATION_SCHEMA.INNODB_SYS_FOREIGN;
ID FOR_NAME REF_NAME N_COLS TYPE
SELECT * FROM INFORMATION_SCHEMA.INNODB_SYS_FOREIGN_COLS;
ID FOR_COL_NAME REF_COL_NAME POS
SELECT t2.name, t1.name FROM information_schema.innodb_sys_columns t1, information_schema.innodb_sys_tables t2 WHERE t1.table_id = t2.table_id AND t2.name LIKE "%child" ORDER BY t1.name;
name name
test/child a1
test/child a2
SELECT NAME FROM information_schema.INNODB_SYS_TABLES;
NAME
SYS_FOREIGN
SYS_FOREIGN_COLS
SYS_VIRTUAL
mysql/innodb_index_stats
mysql/innodb_table_stats
mysql/transaction_registry
test/child
test/parent
ALTER TABLE child ADD PRIMARY KEY idx (a3), CHANGE a1 a3 INT,
ADD CONSTRAINT fk_1 FOREIGN KEY (a2) REFERENCES parent(b)
ON DELETE SET NULL ON UPDATE CASCADE,
ALGORITHM = INPLACE;
Warnings:
Warning 1280 Name 'idx' ignored for PRIMARY key.
SELECT * FROM INFORMATION_SCHEMA.INNODB_SYS_FOREIGN;
ID FOR_NAME REF_NAME N_COLS TYPE
test/fk_1 test/child test/parent 1 6
SELECT * FROM INFORMATION_SCHEMA.INNODB_SYS_FOREIGN_COLS;
ID FOR_COL_NAME REF_COL_NAME POS
test/fk_1 a2 b 0
SELECT t2.name, t1.name FROM information_schema.innodb_sys_columns t1, information_schema.innodb_sys_tables t2 WHERE t1.table_id = t2.table_id AND t2.name LIKE "%child" ORDER BY t1.name;
name name
test/child a2
test/child a3
SELECT NAME FROM information_schema.INNODB_SYS_TABLES;
NAME
SYS_FOREIGN
SYS_FOREIGN_COLS
SYS_VIRTUAL
mysql/innodb_index_stats
mysql/innodb_table_stats
mysql/transaction_registry
test/child
test/parent
SHOW CREATE TABLE child;
Table Create Table
child CREATE TABLE `child` (
`a3` int(11) NOT NULL,
`a2` int(11) DEFAULT NULL,
PRIMARY KEY (`a3`),
KEY `tb` (`a2`),
CONSTRAINT `fk_1` FOREIGN KEY (`a2`) REFERENCES `parent` (`b`) ON DELETE SET NULL ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE child;
CREATE TABLE child (a1 INT NOT NULL, a2 INT) ENGINE = InnoDB;
ALTER TABLE child ADD PRIMARY KEY idx (a1),
ADD CONSTRAINT fk_1 FOREIGN KEY (a2) REFERENCES parent(b)
ON DELETE SET NULL ON UPDATE CASCADE,
ALGORITHM = INPLACE;
Warnings:
Warning 1280 Name 'idx' ignored for PRIMARY key.
SELECT * from information_schema.INNODB_SYS_FOREIGN;
ID FOR_NAME REF_NAME N_COLS TYPE
test/fk_1 test/child test/parent 1 6
SELECT * from information_schema.INNODB_SYS_FOREIGN_COLS;
ID FOR_COL_NAME REF_COL_NAME POS
test/fk_1 a2 b 0
SELECT t2.name, t1.name FROM information_schema.innodb_sys_columns t1, information_schema.innodb_sys_tables t2 WHERE t1.table_id = t2.table_id AND t2.name LIKE "%child" ORDER BY t1.name;
name name
test/child a1
test/child a2
SELECT NAME FROM information_schema.INNODB_SYS_TABLES;
NAME
SYS_FOREIGN
SYS_FOREIGN_COLS
SYS_VIRTUAL
mysql/innodb_index_stats
mysql/innodb_table_stats
mysql/transaction_registry
test/child
test/parent
SHOW CREATE TABLE child;
Table Create Table
child CREATE TABLE `child` (
`a1` int(11) NOT NULL,
`a2` int(11) DEFAULT NULL,
PRIMARY KEY (`a1`),
KEY `fk_1` (`a2`),
CONSTRAINT `fk_1` FOREIGN KEY (`a2`) REFERENCES `parent` (`b`) ON DELETE SET NULL ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE child;
CREATE TABLE child (a1 INT NOT NULL, a2 INT) ENGINE = InnoDB;
ALTER TABLE child CHANGE a1 a3 INT,
ADD CONSTRAINT fk_1 FOREIGN KEY (a3) REFERENCES parent(b)
ON DELETE SET NULL ON UPDATE CASCADE,
ALGORITHM = INPLACE;
SELECT * from information_schema.INNODB_SYS_FOREIGN;
ID FOR_NAME REF_NAME N_COLS TYPE
test/fk_1 test/child test/parent 1 6
SELECT * from information_schema.INNODB_SYS_FOREIGN_COLS;
ID FOR_COL_NAME REF_COL_NAME POS
test/fk_1 a3 b 0
SELECT t2.name, t1.name FROM information_schema.innodb_sys_columns t1, information_schema.innodb_sys_tables t2 WHERE t1.table_id = t2.table_id AND t2.name LIKE "%child" ORDER BY t1.name;
name name
test/child a2
test/child a3
SELECT NAME FROM information_schema.INNODB_SYS_TABLES;
NAME
SYS_FOREIGN
SYS_FOREIGN_COLS
SYS_VIRTUAL
mysql/innodb_index_stats
mysql/innodb_table_stats
mysql/transaction_registry
test/child
test/parent
SHOW CREATE TABLE child;
Table Create Table
child CREATE TABLE `child` (
`a3` int(11) DEFAULT NULL,
`a2` int(11) DEFAULT NULL,
KEY `fk_1` (`a3`),
CONSTRAINT `fk_1` FOREIGN KEY (`a3`) REFERENCES `parent` (`b`) ON DELETE SET NULL ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE child;
CREATE TABLE child (a1 INT NOT NULL, a2 INT) ENGINE = InnoDB;
ALTER TABLE child ADD PRIMARY KEY idx (a3), CHANGE a1 a3 INT,
ADD CONSTRAINT fk_1 FOREIGN KEY (a3) REFERENCES parent(b)
ON DELETE SET NULL ON UPDATE CASCADE,
ALGORITHM = INPLACE;
ERROR HY000: Failed to add the foreign key constraint on table 'child'. Incorrect options in FOREIGN KEY constraint 'test/fk_1'
DROP TABLE parent;
DROP TABLE child;
CREATE TABLE parent (a INT PRIMARY KEY, b INT NOT NULL, c INT) ENGINE = InnoDB;
INSERT INTO parent VALUES(1,2,3),(2,3,4);
CREATE INDEX tb ON parent(b);
CREATE TABLE child (a1 INT NOT NULL, a2 INT, a3 INT) ENGINE = InnoDB;
CREATE INDEX tb ON child(a2);
ALTER TABLE child
ADD CONSTRAINT fk_a FOREIGN KEY (a2) REFERENCES parent(b)
ON DELETE SET NULL ON UPDATE CASCADE,
ALGORITHM = INPLACE;
ALTER TABLE child
ADD CONSTRAINT fk_b FOREIGN KEY (a1) REFERENCES parent(a),
ALGORITHM = INPLACE;
ALTER TABLE child CHANGE a2 a2_new INT, CHANGE a1 a1_new INT;
SHOW CREATE TABLE child;
Table Create Table
child CREATE TABLE `child` (
`a1_new` int(11) DEFAULT NULL,
`a2_new` int(11) DEFAULT NULL,
`a3` int(11) DEFAULT NULL,
KEY `tb` (`a2_new`),
KEY `fk_b` (`a1_new`),
CONSTRAINT `fk_a` FOREIGN KEY (`a2_new`) REFERENCES `parent` (`b`) ON DELETE SET NULL ON UPDATE CASCADE,
CONSTRAINT `fk_b` FOREIGN KEY (`a1_new`) REFERENCES `parent` (`a`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
SELECT * from information_schema.INNODB_SYS_FOREIGN;
ID FOR_NAME REF_NAME N_COLS TYPE
test/fk_a test/child test/parent 1 6
test/fk_b test/child test/parent 1 0
SELECT * from information_schema.INNODB_SYS_FOREIGN_COLS;
ID FOR_COL_NAME REF_COL_NAME POS
test/fk_a a2_new b 0
test/fk_b a1_new a 0
ALTER TABLE child
ADD CONSTRAINT fk_new_1 FOREIGN KEY (a1_new) REFERENCES parent(b),
ADD CONSTRAINT fk_new_2 FOREIGN KEY (a2_new) REFERENCES parent(a),
ADD CONSTRAINT fk_new_3 FOREIGN KEY (a3) REFERENCES parent(c),
ALGORITHM = INPLACE;
ERROR HY000: Failed to add the foreign key constraint. Missing index for constraint 'fk_new_3' in the referenced table 'parent'
SHOW CREATE TABLE child;
Table Create Table
child CREATE TABLE `child` (
`a1_new` int(11) DEFAULT NULL,
`a2_new` int(11) DEFAULT NULL,
`a3` int(11) DEFAULT NULL,
KEY `tb` (`a2_new`),
KEY `fk_b` (`a1_new`),
CONSTRAINT `fk_a` FOREIGN KEY (`a2_new`) REFERENCES `parent` (`b`) ON DELETE SET NULL ON UPDATE CASCADE,
CONSTRAINT `fk_b` FOREIGN KEY (`a1_new`) REFERENCES `parent` (`a`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
SELECT * from information_schema.INNODB_SYS_FOREIGN;
ID FOR_NAME REF_NAME N_COLS TYPE
test/fk_a test/child test/parent 1 6
test/fk_b test/child test/parent 1 0
SELECT * from information_schema.INNODB_SYS_FOREIGN_COLS;
ID FOR_COL_NAME REF_COL_NAME POS
test/fk_a a2_new b 0
test/fk_b a1_new a 0
ALTER TABLE child
ADD CONSTRAINT fk_new_1 FOREIGN KEY (a1_new) REFERENCES parent(b),
ADD CONSTRAINT fk_new_2 FOREIGN KEY (a2_new) REFERENCES parent(a),
ADD CONSTRAINT fk_new_3 FOREIGN KEY (a3) REFERENCES parent(a),
ALGORITHM = INPLACE;
SHOW CREATE TABLE child;
Table Create Table
child CREATE TABLE `child` (
`a1_new` int(11) DEFAULT NULL,
`a2_new` int(11) DEFAULT NULL,
`a3` int(11) DEFAULT NULL,
KEY `tb` (`a2_new`),
KEY `fk_new_1` (`a1_new`),
KEY `fk_new_3` (`a3`),
CONSTRAINT `fk_a` FOREIGN KEY (`a2_new`) REFERENCES `parent` (`b`) ON DELETE SET NULL ON UPDATE CASCADE,
CONSTRAINT `fk_b` FOREIGN KEY (`a1_new`) REFERENCES `parent` (`a`),
CONSTRAINT `fk_new_1` FOREIGN KEY (`a1_new`) REFERENCES `parent` (`b`),
CONSTRAINT `fk_new_2` FOREIGN KEY (`a2_new`) REFERENCES `parent` (`a`),
CONSTRAINT `fk_new_3` FOREIGN KEY (`a3`) REFERENCES `parent` (`a`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
SELECT * from information_schema.INNODB_SYS_FOREIGN;
ID FOR_NAME REF_NAME N_COLS TYPE
test/fk_a test/child test/parent 1 6
test/fk_b test/child test/parent 1 0
test/fk_new_1 test/child test/parent 1 0
test/fk_new_2 test/child test/parent 1 0
test/fk_new_3 test/child test/parent 1 0
SELECT * from information_schema.INNODB_SYS_FOREIGN_COLS;
ID FOR_COL_NAME REF_COL_NAME POS
test/fk_a a2_new b 0
test/fk_b a1_new a 0
test/fk_new_1 a1_new b 0
test/fk_new_2 a2_new a 0
test/fk_new_3 a3 a 0
DROP TABLE child;
CREATE TABLE child (a1 INT NOT NULL, a2 INT, a3 INT) ENGINE = InnoDB;
CREATE INDEX tb ON child(a2);
ALTER TABLE child ADD PRIMARY KEY idx (a1),
ADD CONSTRAINT fk_new_1 FOREIGN KEY (a1) REFERENCES parent(b),
ADD CONSTRAINT fk_new_2 FOREIGN KEY (a2) REFERENCES parent(a),
ADD CONSTRAINT fk_new_3 FOREIGN KEY (a3) REFERENCES parent(c),
ALGORITHM = INPLACE;
ERROR HY000: Failed to add the foreign key constraint. Missing index for constraint 'fk_new_3' in the referenced table 'parent'
SHOW CREATE TABLE child;
Table Create Table
child CREATE TABLE `child` (
`a1` int(11) NOT NULL,
`a2` int(11) DEFAULT NULL,
`a3` int(11) DEFAULT NULL,
KEY `tb` (`a2`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
SELECT * from information_schema.INNODB_SYS_FOREIGN;
ID FOR_NAME REF_NAME N_COLS TYPE
SELECT * from information_schema.INNODB_SYS_FOREIGN_COLS;
ID FOR_COL_NAME REF_COL_NAME POS
ALTER TABLE child ADD PRIMARY KEY idx (a1),
ADD CONSTRAINT fk_new_1 FOREIGN KEY (a1) REFERENCES parent(b),
ADD CONSTRAINT fk_new_2 FOREIGN KEY (a2) REFERENCES parent(a),
ADD CONSTRAINT fk_new_3 FOREIGN KEY (a3) REFERENCES parent(a),
ALGORITHM = INPLACE;
Warnings:
Warning 1280 Name 'idx' ignored for PRIMARY key.
SHOW CREATE TABLE child;
Table Create Table
child CREATE TABLE `child` (
`a1` int(11) NOT NULL,
`a2` int(11) DEFAULT NULL,
`a3` int(11) DEFAULT NULL,
PRIMARY KEY (`a1`),
KEY `tb` (`a2`),
KEY `fk_new_3` (`a3`),
CONSTRAINT `fk_new_1` FOREIGN KEY (`a1`) REFERENCES `parent` (`b`),
CONSTRAINT `fk_new_2` FOREIGN KEY (`a2`) REFERENCES `parent` (`a`),
CONSTRAINT `fk_new_3` FOREIGN KEY (`a3`) REFERENCES `parent` (`a`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
SELECT * from information_schema.INNODB_SYS_FOREIGN;
ID FOR_NAME REF_NAME N_COLS TYPE
test/fk_new_1 test/child test/parent 1 0
test/fk_new_2 test/child test/parent 1 0
test/fk_new_3 test/child test/parent 1 0
SELECT * from information_schema.INNODB_SYS_FOREIGN_COLS;
ID FOR_COL_NAME REF_COL_NAME POS
test/fk_new_1 a1 b 0
test/fk_new_2 a2 a 0
test/fk_new_3 a3 a 0
SET foreign_key_checks = 1;
DROP TABLE child;
DROP TABLE parent;
CREATE TABLE Parent (a INT PRIMARY KEY, b INT NOT NULL) ENGINE = InnoDB;
INSERT INTO Parent VALUES(1,2),(2,3);
CREATE INDEX tb ON Parent(b);
INSERT INTO Parent VALUES(10,20),(20,30);
CREATE TABLE Child (a1 INT PRIMARY KEY, a2 INT) ENGINE = InnoDB;
CREATE INDEX tb ON Child(a2);
INSERT INTO Child VALUES(10,20);
SET foreign_key_checks = 0;
ALTER TABLE Child ADD CONSTRAINT fk_1 FOREIGN KEY (a2)
REFERENCES Parent(b) ON DELETE SET NULL ON UPDATE CASCADE,
ALGORITHM = INPLACE;
DROP TABLE Child;
DROP TABLE Parent;
CREATE TABLE `t2`(a int,c int,d int) ENGINE=INNODB;
CREATE TABLE `t3`(a int,c int,d int) ENGINE=INNODB;
CREATE INDEX idx ON t3(a);
ALTER TABLE `t2` ADD CONSTRAINT `fw` FOREIGN KEY (`c`) REFERENCES t3 (a);
ALTER TABLE `t2` ADD CONSTRAINT `e` foreign key (`d`) REFERENCES t3(a);
ALTER TABLE `t3` ADD CONSTRAINT `e` foreign key (`c`) REFERENCES `t2`(`c`) ON UPDATE SET NULL;
ERROR HY000: Failed to add the foreign key constraint 'test/e' to system tables
SELECT * FROM INFORMATION_SCHEMA.INNODB_SYS_FOREIGN;
ID FOR_NAME REF_NAME N_COLS TYPE
test/e test/t2 test/t3 1 0
test/fw test/t2 test/t3 1 0
SELECT * FROM INFORMATION_SCHEMA.INNODB_SYS_FOREIGN_COLS;
ID FOR_COL_NAME REF_COL_NAME POS
test/e d a 0
test/fw c a 0
DROP TABLE t2;
DROP TABLE t3;
# Bug #17449901 TABLE DISAPPEARS WHEN ALTERING
# WITH FOREIGN KEY CHECKS OFF
create table t1(f1 int,primary key(f1))engine=innodb;
create table t2(f2 int,f3 int,key t(f2,f3),foreign key(f2) references t1(f1))engine=innodb;
SET foreign_key_checks=0;
drop index t on t2;
drop table t2;
drop table t1;
create table t1(f1 int ,primary key(f1))engine=innodb;
create table t2(f2 int,f3 int, key t(f2),foreign key(f2) references t1(f1))engine=innodb;
SET foreign_key_checks = 0;
alter table t2 drop key t,algorithm=inplace;
show create table t2;
Table Create Table
t2 CREATE TABLE `t2` (
`f2` int(11) DEFAULT NULL,
`f3` int(11) DEFAULT NULL,
CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`f2`) REFERENCES `t1` (`f1`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t2;
drop table t1;
create table t1(f1 int ,primary key(f1))engine=innodb;
create table t2(f2 int,f3 int, key t(f2),key t1(f2,f3),
foreign key(f2) references t1(f1))engine=innodb;
SET foreign_key_checks = 0;
alter table t2 drop key t,algorithm=inplace;
show create table t2;
Table Create Table
t2 CREATE TABLE `t2` (
`f2` int(11) DEFAULT NULL,
`f3` int(11) DEFAULT NULL,
KEY `t1` (`f2`,`f3`),
CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`f2`) REFERENCES `t1` (`f1`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
drop table t2;
drop table t1;
#
# MDEV-29092 FOREIGN_KEY_CHECKS does not prevent non-copy
# alter from creating invalid FK structures
#
CREATE TABLE t1(f1 INT, KEY(f1),
FOREIGN KEY(f1) references t1(f1))ENGINE=InnoDB;
SHOW CREATE TABLE t1;
Table Create Table
t1 CREATE TABLE `t1` (
`f1` int(11) DEFAULT NULL,
KEY `f1` (`f1`),
CONSTRAINT `t1_ibfk_1` FOREIGN KEY (`f1`) REFERENCES `t1` (`f1`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t1;
CREATE TABLE t1(f1 INT, KEY(f1),
FOREIGN KEY(f1) REFERENCES t1(f1))ENGINE=InnoDB;
SHOW CREATE TABLE t1;
Table Create Table
t1 CREATE TABLE `t1` (
`f1` int(11) DEFAULT NULL,
KEY `f1` (`f1`),
CONSTRAINT `t1_ibfk_1` FOREIGN KEY (`f1`) REFERENCES `t1` (`f1`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
ALTER TABLE t1 DROP KEY f1;
SHOW CREATE TABLE t1;
Table Create Table
t1 CREATE TABLE `t1` (
`f1` int(11) DEFAULT NULL,
CONSTRAINT `t1_ibfk_1` FOREIGN KEY (`f1`) REFERENCES `t1` (`f1`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
DROP TABLE t1;
|
