a

Semester 2/SQL Hell pt4.txt

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+/* What are the suppliers that supply all parts using NOT EXISTS */
+/* sp difference A */
+select DISTINCT snumber
+from spj as c
+where not EXISTS 
+/* A */
+/* Cross Product */
+(select DISTINCT b.snumber
+ from part as a cross join spj as b 
+ where c.snumber = b.snumber and not EXISTS
+ /* difference cross product sp */
+ (select snumber, pnumber from spj
+  where b.snumber = spj.snumber and a.pnumber = spj.pnumber));
+
+  
+  /* What are the suppliers that supply all parts using NOT EXISTS * */
+/* sp difference A */
+select DISTINCT snumber
+from spj as c
+where not EXISTS 
+/* A */
+/* Cross Product */
+(select *
+ from part as a cross join spj as b 
+ where c.snumber = b.snumber and not EXISTS
+ /* difference cross product sp */
+ (select * from spj
+  where b.snumber = spj.snumber and a.pnumber = spj.pnumber));
+  
+  
+/* What are the suppliers that supply all parts using NOT EXISTS *, list their names and their cities */
+select snumber, sname, city from supplier
+WHERE snumber in
+(/* sp difference A */
+select DISTINCT snumber
+from spj as c
+where not EXISTS 
+/* A */
+/* Cross Product */
+(select *
+ from part as a cross join spj as b 
+ where c.snumber = b.snumber and not EXISTS
+ /* difference cross product sp */
+ (select * from spj
+  where b.snumber = spj.snumber and a.pnumber = spj.pnumber)));