Sams Teach Yourself MySQL

Using Wildcards

You can grant privileges to usernames that match wildcard criteria by using the % and _ wildcard characters in the username.

You might actually want to create a user that can access the database from any remote host using the same username and password without needing to create a separate username for each possible host. Using % as the host part of the username accomplishes this, as shown in the following example:

mysql> CREATE USER 'chris@%' IDENTIFIED BY 'password';
Query OK, 0 rows affected (0.00 sec)

mysql> GRANT SELECT, INSERT
    -> ON mysql10.products
    -> TO 'chris@%';
Query OK, 0 rows affected (0.00 sec)

Wildcard Usernames

The username in a CREATE USER, GRANT, or REVOKE command must be enclosed in quotes if it contains ...