Создание read-only пользователя в MySQL

grant select on database_name.* to 'user_name'@'%' identified by 'password';

или

grant select on database_name.* to 'user_name' identified by 'password';

или

grant select on database_name.* to 'user_name'@'host_name_or_IP' identified by 'password';

и

flush privileges;