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
|
stop slave;
drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
reset master;
reset slave;
drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
start slave;
create table t1 (a int not null auto_increment,b int, primary key (a)) engine=myisam auto_increment=3;
insert into t1 values (NULL,1),(NULL,2),(NULL,3);
select * from t1;
a b
12 1
22 2
32 3
select * from t1;
a b
12 1
22 2
32 3
drop table t1;
create table t1 (a int not null auto_increment,b int, primary key (a)) engine=myisam;
insert into t1 values (1,1),(NULL,2),(3,3),(NULL,4);
delete from t1 where b=4;
insert into t1 values (NULL,5),(NULL,6);
select * from t1;
a b
1 1
2 2
3 3
22 5
32 6
select * from t1;
a b
1 1
2 2
3 3
22 5
32 6
drop table t1;
set @@session.auto_increment_increment=100, @@session.auto_increment_offset=10;
show variables like "%auto_inc%";
Variable_name Value
auto_increment_increment 100
auto_increment_offset 10
create table t1 (a int not null auto_increment, primary key (a)) engine=myisam;
insert into t1 values (NULL),(5),(NULL);
insert into t1 values (250),(NULL);
select * from t1;
a
5
10
110
250
310
insert into t1 values (1000);
set @@insert_id=400;
insert into t1 values(NULL),(NULL);
select * from t1;
a
5
10
110
250
310
400
410
1000
select * from t1;
a
5
10
110
250
310
400
410
1000
drop table t1;
create table t1 (a int not null auto_increment, primary key (a)) engine=innodb;
insert into t1 values (NULL),(5),(NULL);
insert into t1 values (250),(NULL);
select * from t1;
a
5
10
110
250
310
insert into t1 values (1000);
set @@insert_id=400;
insert into t1 values(NULL),(NULL);
select * from t1;
a
5
10
110
250
310
400
410
1000
select * from t1;
a
5
10
110
250
310
400
410
1000
drop table t1;
set @@session.auto_increment_increment=1, @@session.auto_increment_offset=1;
create table t1 (a int not null auto_increment, primary key (a)) engine=myisam;
insert into t1 values (NULL),(5),(NULL),(NULL);
insert into t1 values (500),(NULL),(502),(NULL),(NULL);
select * from t1;
a
1
5
6
7
500
501
502
503
504
set @@insert_id=600;
insert into t1 values(600),(NULL),(NULL);
ERROR 23000: Duplicate entry '600' for key 1
set @@insert_id=600;
insert ignore into t1 values(600),(NULL),(NULL),(610),(NULL);
select * from t1;
a
1
5
6
7
500
501
502
503
504
600
610
611
select * from t1;
a
1
5
6
7
500
501
502
503
504
600
610
611
drop table t1;
set @@session.auto_increment_increment=10, @@session.auto_increment_offset=1;
create table t1 (a int not null auto_increment, primary key (a)) engine=myisam;
insert into t1 values(2),(12),(22),(32),(42);
insert into t1 values (NULL),(NULL);
insert into t1 values (3),(NULL),(NULL);
select * from t1;
a
1
3
11
21
31
select * from t1;
a
1
2
3
11
12
21
22
31
32
42
drop table t1;
|
