SELECT name FROM member WHERE member_id NOT IN (SELECT member_id FROM membership_register_branch)
Show member names without any registered branch.
[Schema (values) (types)]: | shop_membership |  member : member_id (text) , card_number (number) , name (text) , hometown (text) , level (text) | branch : branch_id (text) , name (number) , open_year (text) , address_road (text) , city (text) , membership_amount (number) | membership_register_branch : member_id (text) , branch_id (number) , register_year (text) | purchase : member_id (text) , branch_id (number) , year (text) , total_pounds (text);