MySQL 8.0

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select version();


version()


8.0.30


-- You might be careful, using 'serial' alias 
create table iuds_test(id serial, textval varchar(100), numval bigint, dateval datetime);
insert into iuds_test 
  (textval, numval, dateval) values
  ('first', 1, now());
insert into iuds_test 
  (id, textval, numval, dateval) values
  (42,'manual id ignoring type', 2, now());
insert into iuds_test 
  (textval, numval, dateval) values
  ('3rd', 3, now());
select * from iuds_test;
-- interesting, we skipped some id by forcing one
-- maybe we can try to do other weird things


id
textval
numval
dateval


1
first
1
2022-10-31 21:09:21

42
manual id ignoring type
2
2022-10-31 21:09:21

43
3rd
3
2022-10-31 21:09:21


update iuds_test 
   set id = 2,
       textval = 'You are unlikely to do this, in case it is a real primary key!'
where id = 42;

Rows matched: 1  Changed: 1  Warnings: 0


select * from iuds_test;


id
textval
numval
dateval


1
first
1
2022-10-31 21:09:21

2
You are unlikely to do this, in case it is a real primary key!
2
2022-10-31 21:09:21

43
3rd
3
2022-10-31 21:09:21


delete from iuds_test
 where id = 43;
select * from iuds_test;


id
textval
numval
dateval


1
first
1
2022-10-31 21:09:21

2
You are unlikely to do this, in case it is a real primary key!
2
2022-10-31 21:09:21


/* You hardly want to sleep(), while executing SQL (except nobody is looking) */
do sleep(2);
insert into iuds_test (textval, numval, dateval)
select textval, numval, now() from iuds_test;

Records: 2  Duplicates: 0  Warnings: 0


select * from iuds_test;


id
textval
numval
dateval


1
first
1
2022-10-31 21:09:21

2
You are unlikely to do this, in case it is a real primary key!
2
2022-10-31 21:09:21

44
first
1
2022-10-31 21:09:23

45
You are unlikely to do this, in case it is a real primary key!
2
2022-10-31 21:09:23


-- man könnte noch eine Menge andere Dinge ausprobieren 
-- not a good idea! 
insert into iuds_test 
select * from iuds_test;
-- but who cares, it's not Yours ;)

delete * from iuds_test;
-- it really makes no difference here

Duplicate entry '1' for key 'iuds_test.id'

id	textval	numval	dateval
1	first	1	2022-10-31 21:09:21
42	manual id ignoring type	2	2022-10-31 21:09:21
43	3rd	3	2022-10-31 21:09:21

id	textval	numval	dateval
1	first	1	2022-10-31 21:09:21
2	You are unlikely to do this, in case it is a real primary key!	2	2022-10-31 21:09:21
43	3rd	3	2022-10-31 21:09:21