a

Semester 2/SQL Hell pt3.txt

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+/* list suppliers who have QTYs greater than the the QTYs of s4 */
+select snumber, qty
+from spj
+where qty > ALL
+(select qty
+from spj
+where snumber = 's4');
+
+
+/*List suppliers who have qty smaller than any qty of s2*/
+
+SELECT snumber, qty
+FROM spj
+WHERE qty < ANY(SELECT qty FROM spj WHERE snumber = "s2");
+
+/*List the snumber and QTYs of the supplier who relates with the snumber to the QTYs that are greater than the AVG QTYs of the particular supplier.
+i.e. for s1 the AVG of all its QTY is x... You must list all the QTYs of s1 that are greater than x.
+*/
+select snumber, qty
+from spj as a 
+where qty > 
+(select avg(qty)
+ from spj
+ where a.snumber = snumber);
+ 
+ 
+ /* EXISTS demo */
+ 
+ select *
+from supplier a
+where not EXISTS
+	(select * from spj
+    where snumber = a.snumber);

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)));