如何在 MySQL 中将自动增量格式设置为 0001？
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How can I set autoincrement format to 0001 in MySQL?
提问by 32.
How can I make MySQL auto increment in 4 digit format?
如何使 MySQL 以 4 位格式自动递增？
So instead of '1' make '0001'?
所以不是'1'而是'0001'？
回答by Jeremy L
Try adding ZEROFILL attribute to the field.
尝试将 ZEROFILL 属性添加到该字段。
回答by Paul Dixon
Could you leave it as an integer and format it for humans in your SQL, for example, to pad with zeros to 4 chars wide
您能否将其保留为整数并在您的 SQL 中为人类设置格式，例如，用零填充到 4 个字符宽
select lpad(idcolumn,4,'0') from mytable;
Or use zerofill and specify the desired width when declaring the table:
或者在声明表格时使用 zerofill 并指定所需的宽度：
create table tmpfoo (
mykey int(6) zerofill not null auto_increment,
primary key(mykey)
);
insert into tmpfoo values(1),(2);
select * from tmpfoo;
+--------+
| mykey |
+--------+
| 000001 |
| 000002 |
+--------+
回答by gahooa
MySQL supports ZEROFILLon integer columns:
MySQL在整数列上支持 ZEROFILL：
mysql> create table foo (the_key int unsigned zerofill not null
auto_increment primary key);
Query OK, 0 rows affected (0.21 sec)
mysql> insert into foo SET the_key = Null;
Query OK, 1 row affected (0.00 sec)
...
mysql> insert into foo SET the_key = Null;
Query OK, 1 row affected (0.00 sec)
mysql> select * from foo;
+------------+
| the_key |
+------------+
| 0000000001 |
| 0000000002 |
| 0000000003 |
| 0000000004 |
| 0000000005 |
| 0000000006 |
| 0000000007 |
| 0000000008 |
+------------+
8 rows in set (0.00 sec)
You may need to look into using a smallint (5 digits), or trimming/padding.
您可能需要考虑使用 smallint（5 位数字）或修剪/填充。
回答by jonstjohn
If you need the auto_increment column in a zero padded format, I suggest that you display it as such and not attempt to store it in the database that way.
如果您需要零填充格式的 auto_increment 列，我建议您按原样显示它，而不是尝试以这种方式将其存储在数据库中。
In PHP, you could use the following code to display or otherwise use the id:
在 PHP 中，您可以使用以下代码来显示或以其他方式使用 id：
$padded_id = str_pad($id, 4, '0');
回答by Hawk Kroeger
回答by Steven A. Lowe
is the field an integer? if so, the answer is, "why? it's an integer!" ;-)
该字段是整数吗？如果是这样，答案是，“为什么？它是一个整数！” ;-)
