Yurttas/PL/DBL/mssql/F/01/Company-B/q08.sql

 1/*
 2REM
 3REM q08.sql
 4REM
 5REM Assume the companies may be located in several cities.
 6REM Find all companies located in every city in which
 7REM 'Small Bank Corporation' is located.
 8REM
 9*/
10
11SELECT DISTINCT C1.companyname 
12FROM Company C1
13WHERE NOT EXISTS
14            (SELECT city 
15             FROM Company 
16             WHERE companyname='Small Bank Corporation' 
17               AND city NOT IN (SELECT C2.city 
18                                FROM Company C2 
19                                WHERE C1.companyname = C2.companyname)) 
20  AND C1.companyname <> 'Small Bank Corporation';