CREATE TABLE purchase (member_id NUMBER, branch_id CLOB, year CLOB, total_pounds NUMBER)
CREATE TABLE member (member_id NUMBER, card_number CLOB, name CLOB, hometown CLOB, level NUMBER)
CREATE TABLE branch (branch_id NUMBER, name CLOB, open_year CLOB, address_road CLOB, city CLOB, membership_amount CLOB)
CREATE TABLE membership_register_branch (member_id NUMBER, branch_id CLOB, register_year CLOB)

Show all cities without a branch having more than 100 memberships.
SELECT city FROM branch EXCEPT SELECT city FROM branch WHERE membership_amount > 100
SELECT "city" FROM "branch" EXCEPT SELECT "city" FROM "branch" WHERE "membership_amount" > 100