mysql - 是否可以将 varchar 限制为 MySQL 中的特定字符集？

Question

我正在创建一个网站，其中特定的用户数据应仅包含特定预先指定集中的字符。在将数据插入数据库之前，我可以使用 PHP 验证数据。但我想知道这在 MySQL 本身是否可行。

For instance, consider the Username. It should have characters only from the Alphanumeric set and underscore. Verification of this data is possible through PHP before inserting it into the database. But is it possible to assign a constrain to the Varchar column to not allow any string, with characters other than these, to be inserted into the table?

Answer 1

你问了

Is it possible to assign a constraint to the Varchar column to not allow any string, with characters other than these, to be inserted into the table?

答案是否定的。 MySQL 的约束并不那么聪明。