CREATE TABLE purchase (member_id NUMBER, branch_id CLOB, year CLOB, total_pounds NUMBER)
CREATE TABLE membership_register_branch (member_id NUMBER, branch_id CLOB, register_year CLOB)
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)

Show minimum and maximum amount of memberships for all branches opened in 2011 or located at city London.
SELECT MIN(membership_amount), MAX(membership_amount) FROM branch WHERE open_year = 2011 OR city = 'London'
SELECT MIN("membership_amount"), MAX("membership_amount") FROM "branch" WHERE "city" = 'London' OR "open_year" = 2011