MySQL権限管理部------ユーザー権限付与

To accommodate granting rights to users from arbitrary hosts, MySQL supports specifying the user value in the form user_name @ host_name . If a user_name or host_name value is legal as an unquoted identifier, you need not quote it. However, quotes are necessary to specify a user_name string containing special characters (such as “- ”), or a host_name string containing special characters or wildcard characters (such as “% ”); for example, 'test-user'@'test-hostname' . Quote the username and hostname separately.
You can specify wildcards in the hostname. For example, user_name @'%.loc.gov' applies to user_name for any host in the loc.gov user_name @'144.155.166.%' applies to user_name for any host in the 144.155.166 class C subnet. domain, and
The simple form user_name is a synonym for user_name @'%' .
user_nameはuser_name@'%'と じ です.