在 MySQL 中显示自动递增用户 ID 序列号从 001 开始?
mysqlmysqli database
为此，使用 ZEROFILL 并更改表以从相同序列开始 −
alter table yourTableName change yourColumnName yourColumnName int(3) UNSIGNED ZEROFILL NOT NULL AUTO_INCREMENT PRIMARY KEY;
为了理解上述语法，让我们首先创建一个表 −
mysql> create table DemoTable1958 ( UserId int, UserName varchar(20) ); Query OK, 0 rows affected (0.00 sec)
以下查询用于将生成的序列号更改为从 001 开始:
mysql> alter table DemoTable1958 change UserId UserId int(3) UNSIGNED ZEROFILL NOT NULL AUTO_INCREMENT PRIMARY KEY; Query OK, 0 rows affected (0.00 sec) Records: 0 Duplicates: 0 Warnings: 0
让我们检查一下表描述:
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 insert 命令在表中插入一些记录 −
mysql> insert into DemoTable1958(UserName) values('Chris');
Query OK, 1 row affected (0.00 sec)
mysql> insert into DemoTable1958(UserName) values('David');
Query OK, 1 row affected (0.00 sec)
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)
