create table a(
sn bigint (20) not null auto_increment,
data varchar (500),
primary key(sn)
)auto_increment = 100;
步长为2如何写,即是sn是100,102,104,106......
sn bigint (20) not null auto_increment,
data varchar (500),
primary key(sn)
)auto_increment = 100;
步长为2如何写,即是sn是100,102,104,106......
+--------------------------+-------+
| Variable_name | Value |
+--------------------------+-------+
| auto_increment_increment | 1 |
| auto_increment_offset | 1 |
+--------------------------+-------+
2 rows in set (0.00 sec)mysql> CREATE TABLE autoinc1
-> (col INT NOT NULL AUTO_INCREMENT PRIMARY KEY);
Query OK, 0 rows affected (0.04 sec)mysql> SET @@auto_increment_increment=10;
Query OK, 0 rows affected (0.00 sec)mysql> SHOW VARIABLES LIKE 'auto_inc%';
+--------------------------+-------+
| Variable_name | Value |
+--------------------------+-------+
| auto_increment_increment | 10 |
| auto_increment_offset | 1 |
+--------------------------+-------+
2 rows in set (0.01 sec)mysql> INSERT INTO autoinc1 VALUES (NULL), (NULL), (NULL), (NULL);
Query OK, 4 rows affected (0.00 sec)
Records: 4 Duplicates: 0 Warnings: 0mysql> SELECT col FROM autoinc1;
+-----+
| col |
+-----+
| 1 |
| 11 |
| 21 |
| 31 |
+-----+
4 rows in set (0.00 sec)