Query using EXISTS

gistfile1.sql

-- The alternative query for the List 6.
-- This query can be executed against SQL Server.
-- http://gihyo.jp/dev/serial/01/sql_lifesaving/0005?page=4
SELECT s.sup,
       s.city,
       s.area
  FROM Suppliers s
 WHERE s.ship_flg = '可'
   AND EXISTS 
       (SELECT *
          FROM Manufacturers m
         WHERE m.req_flg = '要'
           AND m.city = s.city
           AND m.area = s.area
       )