Yurttas/PL/DBL/mysql/F/01/00/SPJ/q04.sql

 1/*
 2REM
 3REM q04.sql
 4REM
 5REM Get supplier numbers for suppliers who supply
 6REM the same part to all projects.
 7REM
 8*/
 9
10\. set-db.sql
11
12SELECT S.sn
13FROM Suppliers S
14WHERE EXISTS 
15        (SELECT *
16         FROM Parts P
17         WHERE NOT EXISTS 
18                     (SELECT *
19                      FROM Projects J
20                      WHERE NOT EXISTS 
21                                  (SELECT *
22                                   FROM Shipments SPJ
23                                   WHERE SPJ.sn = S.sn
24                                     AND SPJ.pn = P.pn
25                                     AND SPJ.jn = J.jn)));