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auto_increment步长怎么设置

发布时间: 2012-08-24 10:00:21 作者: rapoo

auto_increment步长如何设置
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......

[解决办法]
可以修改系统变量 auto_increment_increment

SQL code
mysql> SHOW VARIABLES LIKE 'auto_inc%';+--------------------------+-------+| 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) 

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