drop table if exists t1;
SET SQL_WARNINGS=1;
create table t1 (a int not null auto_increment,b int, primary key (a)) engine=myisam auto_increment=3;
insert into t1 values (1,1),(NULL,3),(NULL,4);
delete from t1 where a=4;
insert into t1 values (NULL,5),(NULL,6);
select * from t1;
a	b
1	1
3	3
5	5
6	6
delete from t1 where a=6;
replace t1 values (3,1);
ALTER TABLE t1 add c int;
replace t1 values (3,3,3);
insert into t1 values (NULL,7,7);
update t1 set a=8,b=b+1,c=c+1 where a=7;
insert into t1 values (NULL,9,9);
select * from t1;
a	b	c
1	1	NULL
3	3	3
5	5	NULL
8	8	8
9	9	9
drop table t1;
create table t1 (
skey tinyint unsigned NOT NULL auto_increment PRIMARY KEY,
sval char(20)
);
insert into t1 values (NULL, "hello");
insert into t1 values (NULL, "hey");
select * from t1;
skey	sval
1	hello
2	hey
select _rowid,t1._rowid,skey,sval from t1;
_rowid	_rowid	skey	sval
1	1	1	hello
2	2	2	hey
drop table t1;
create table t1 (a char(10) not null, b int not null auto_increment, primary key(a,b));
insert into t1 values ("a",1),("b",2),("a",2),("c",1);
insert into t1 values ("a",NULL),("b",NULL),("c",NULL),("e",NULL);
insert into t1 (a) values ("a"),("b"),("c"),("d");
insert into t1 (a) values ('k'),('d');
insert into t1 (a) values ("a");
insert into t1 values ("d",last_insert_id());
select * from t1;
a	b
a	1
a	2
a	3
a	4
a	5
b	2
b	3
b	4
c	1
c	2
c	3
d	1
d	2
d	5
e	1
k	1
drop table t1;
create table t1 (ordid int(8) not null auto_increment, ord  varchar(50) not null, primary key (ordid), index(ord,ordid));
insert into t1 (ordid,ord) values (NULL,'sdj'),(NULL,'sdj');
select * from t1;
ordid	ord
1	sdj
2	sdj
drop table t1;
create table t1 (ordid int(8) not null auto_increment, ord  varchar(50) not null, primary key (ord,ordid));
insert into t1 values (NULL,'sdj'),(NULL,'sdj'),(NULL,"abc"),(NULL,'abc'),(NULL,'zzz'),(NULL,'sdj'),(NULL,'abc');
select * from t1;
ordid	ord
1	abc
2	abc
3	abc
1	sdj
2	sdj
3	sdj
1	zzz
drop table t1;
create table t1 (sid char(5), id int(2) NOT NULL auto_increment, key(sid,  id));
create table t2 (sid char(20), id int(2));
insert into t2 values ('skr',NULL),('skr',NULL),('test',NULL);
insert into t1 select * from t2;
select * from t1;
sid	id
skr	1
skr	2
test	1
drop table t1,t2;
create table t1 (a int not null primary key auto_increment);
insert into t1 values (0);
update t1 set a=0;
select * from t1;
a
0
check table t1;
Table	Op	Msg_type	Msg_text
test.t1	check	warning	Found row where the auto_increment column has the value 0
test.t1	check	status	OK
drop table t1;
create table t1 (a int not null auto_increment primary key);
insert into t1 values (NULL);
insert into t1 values (-1);
select last_insert_id();
last_insert_id()
1
insert into t1 values (NULL);
select * from t1;
a
-1
1
2
drop table t1;
create table t1 (a int not null auto_increment primary key) /*!40102 engine=heap */;
insert into t1 values (NULL);
insert into t1 values (-1);
select last_insert_id();
last_insert_id()
1
insert into t1 values (NULL);
select * from t1;
a
1
-1
2
drop table t1;
create table t1 (i tinyint unsigned not null auto_increment primary key);
insert into t1 set i = 254;
insert into t1 set i = null;
select last_insert_id();
last_insert_id()
255
explain extended select last_insert_id();
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
Warnings:
Note	1003	select high_priority no_cache last_insert_id() AS `last_insert_id()`
insert into t1 set i = 254;
ERROR 23000: Duplicate entry '254' for key 1
select last_insert_id();
last_insert_id()
255
insert into t1 set i = null;
ERROR 23000: Duplicate entry '255' for key 1
select last_insert_id();
last_insert_id()
0
drop table t1;
create table t1 (i tinyint unsigned not null auto_increment, key (i));
insert into t1 set i = 254;
insert into t1 set i = null;
select last_insert_id();
last_insert_id()
255
insert into t1 set i = null;
Warnings:
Warning	1264	Data truncated, out of range for column 'i' at row 1
select last_insert_id();
last_insert_id()
255
drop table t1;
create table t1 (i tinyint unsigned not null auto_increment primary key, b int, unique (b));
insert into t1 values (NULL, 10);
select last_insert_id();
last_insert_id()
1
insert into t1 values (NULL, 15);
select last_insert_id();
last_insert_id()
2
insert into t1 values (NULL, 10);
ERROR 23000: Duplicate entry '10' for key 2
select last_insert_id();
last_insert_id()
0
drop table t1;
create table t1(a int auto_increment,b int null,primary key(a));
SET SQL_MODE=NO_AUTO_VALUE_ON_ZERO;
insert into t1(a,b)values(NULL,1);
insert into t1(a,b)values(200,2);
insert into t1(a,b)values(0,3);
insert into t1(b)values(4);
insert into t1(b)values(5);
insert into t1(b)values(6);
insert into t1(b)values(7);
select * from t1 order by b;
a	b
1	1
200	2
0	3
201	4
202	5
203	6
204	7
delete from t1 where a=0;
update t1 set a=0 where b=5;
select * from t1 order by b;
a	b
1	1
200	2
201	4
0	5
203	6
204	7
delete from t1 where a=0;
update t1 set a=NULL where b=6;
Warnings:
Warning	1263	Data truncated, NULL supplied to NOT NULL column 'a' at row 4
update t1 set a=300 where b=7;
SET SQL_MODE='';
insert into t1(a,b)values(NULL,8);
insert into t1(a,b)values(400,9);
insert into t1(a,b)values(0,10);
insert into t1(b)values(11);
insert into t1(b)values(12);
insert into t1(b)values(13);
insert into t1(b)values(14);
select * from t1 order by b;
a	b
1	1
200	2
201	4
0	6
300	7
301	8
400	9
401	10
402	11
403	12
404	13
405	14
delete from t1 where a=0;
update t1 set a=0 where b=12;
select * from t1 order by b;
a	b
1	1
200	2
201	4
300	7
301	8
400	9
401	10
402	11
0	12
404	13
405	14
delete from t1 where a=0;
update t1 set a=NULL where b=13;
Warnings:
Warning	1263	Data truncated, NULL supplied to NOT NULL column 'a' at row 9
update t1 set a=500 where b=14;
select * from t1 order by b;
a	b
1	1
200	2
201	4
300	7
301	8
400	9
401	10
402	11
0	13
500	14
drop table t1;