询问有关php的摘要01 + 01 = 02 [英] ask about php summarize 01 + 01 = 02

问题描述

我想在数据库中创建一个ID

I want to make a id in database

id_user =>数据类型'varchar'

id_user => data type 'varchar'

我希望我的ID以00，01，02等开头. 为了创建新的ID，我对所有行进行计数，计数结果将加01.

I want my id to start from 00, 01, 02, and so on. And to make new id, I count the all the rows, and the result from count will be added by 01.

示例:

$id=array(00,01,02);
$count_exist_id = $count($id)
$new_id= '00' + $count_exist_id

，我希望新ID必须为'03'，并将其存储在表用户列id_user

and I hope the new id must be '03' and it will be store to database in table user column id_user

推荐答案

您可以使用INT(x) ZEROFILL在数字前加0. '1'=>'001'

You can use INT(x) ZEROFILL, to add 0 before the number. '1' => '001'

使用 INT零填充，您可以拥有AUTO_INCREMENT. ;)

With INT ZEROFILL, you have AUTO_INCREMENT. ;)

CREATE TABLE user (
   id_user INT(8) UNSIGNED ZEROFILL NOT NULL AUTO_INCREMENT, 
   PRIMARY KEY(id_user)
);

如果使用UNSIGNED，则可以优化表，并节省一个BIT，以获得更大的数字.

If you use UNSIGNED, you optimize your table, and you save one BIT, to get bigger number.

请参阅:

• 在MySQL中进行零填充有什么好处?
• 如何在MySQL?
• 未签名"是什么意思?在MySQL中是什么意思以及什么时候使用它?

• What is the benefit of zerofill in MySQL?
• How can I set autoincrement format to 0001 in MySQL?
• What does "unsigned" in MySQL mean and when to use it?

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