为此,请使用ZEROFILL并更改表以从相同顺序开始-
alter table yourTableName change yourColumnName yourColumnName int(3) UNSIGNED ZEROFILL NOT NULL AUTO_INCREMENT PRIMARY KEY;
要了解上述语法,让我们首先创建一个表-
mysql> create table DemoTable1958 ( UserId int, UserName varchar(20) );
这是更改生成的序列号以从001开始的查询:
mysql> alter table DemoTable1958 change UserId UserId int(3) UNSIGNED ZEROFILL NOT NULL AUTO_INCREMENT PRIMARY KEY; Records: 0 Duplicates: 0 Warnings: 0
让我们检查表说明:
mysql> desc DemoTable1958;
这将产生以下输出-
+----------+--------------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +----------+--------------------------+------+-----+---------+----------------+ | UserId | int(3) unsigned zerofill | NO | PRI | NULL | auto_increment | | UserName | varchar(20) | YES | | NULL | | +----------+--------------------------+------+-----+---------+----------------+ 2 rows in set (0.00 sec)
使用插入命令在表中插入一些记录-
mysql> insert into DemoTable1958(UserName) values('Chris'); mysql> insert into DemoTable1958(UserName) values('David');
使用select语句显示表中的所有记录-
mysql> select * from DemoTable1958;
这将产生以下输出-
+--------+----------+ | UserId | UserName | +--------+----------+ | 001 | Chris | | 002 | David | +--------+----------+ 2 rows in set (0.00 sec)