Merge branch 'a2' of tarfeef101/cs348 into master

a2/a2.sql

@@ -0,0 +1,203 @@
+
+-- Current term is 1185
+
+/*
+The student number and name of second year students who have obtained
+a grade lower than 65 in at least two courses in a department with the
+name “computer science”.
+*/
+-- ran on empty
+select distinct sname, snum from student where year = 2 and snum in
+(
+  select snum from mark m1 where grade < 65 and deptcode = 'CS' and snum in
+  (
+    select snum from mark where grade < 65 and deptcode = 'CS' and snum != m1.snum
+  )
+);
+
+/*
+The number and name of professors who are not in the pure math (PM)
+department, and who are teaching CS245 for the first time.
+*/
+-- ran on empty
+select distinct pnum, pname from professor where deptcode not in
+(
+  select deptcode from department where deptname = 'PM'
+) and pnum in
+(
+  select pnum from class where deptcode = 'CS' and cnum = 245 and term = 1185
+) and pnum not in
+(
+  select pnum from class where deptcode = 'CS' and cnum = 245 and term != 1185
+);
+
+/*
+The number, name and year of each student who has obtained a grade in
+CS240 that is within 3 marks of the highest ever grade recorded for that
+course.
+*/
+select s.snum, s.sname, s.year from student s where s.snum in
+(
+  select snum from mark where deptcode = 'CS' and cnum = 240 and grade >= ((select grade from mark where deptcode = 'CS' and cnum = 240 order by grade desc limit 1) - 3)
+);
+
+/*
+ The number and name of students who have completed two years, who
+have a final grade of at least 85 in every computer science course that
+they have taken, and who have always been taught by a professor in the
+computer science (CS) department.
+*/
+select snum, sname from student where year > 2 and snum not in
+(
+  select snum from mark where deptcode = 'CS' and grade < 85
+) and snum not in
+(
+  select e.snum from enrollment e where exists
+  (
+    select * from class c where
+    c.deptcode = e.deptcode and c.cnum = e.cnum and c.term = e.term and c.section = e.section and c.pnum not in
+    (
+      select pnum from professor where deptcode != 'CS'
+    )
+  )
+);
+
+/*
+ A sorted list of all departments who do not have a professor currently
+teaching a course offered by a different department.
+*/
+select deptname from department where deptcode not in
+(
+  select p.deptcode from professor p where pnum in
+  (
+    select pnum from class where term = 1185 and deptcode != p.deptcode and pnum = p.pnum
+  )
+) order by deptname;
+
+/*
+For each pair of classes for the same course that were taught in the same
+term, and that where also taught by different professors: the minimum
+grades obtained and the maximum grades obtained. In addition to these
+four values, each result should include the number and name of each professor,
+as well as the identifying attributes for each class.
+*/
+with combineTable (grade, pname, pnum, deptcode, cnum, term, section) as
+(select m.grade as grade, p.pname as pname, p.pnum as pnum,
+        cl.deptcode as deptcode, cl.cnum as cnum, cl.term as term, cl.section as section
+  from mark m, enrollment e, class cl, course co, professor p
+  where m.snum = e.snum and m.deptcode = e.deptcode and m.cnum = e.cnum and m.term = e.term and m.section = e.section
+      and
+      cl.deptcode = e.deptcode and cl.cnum = e.cnum and cl.term = e.term and cl.section = e.section
+      and
+      cl.deptcode = co.deptcode and cl.cnum = co.cnum
+      and
+      cl.pnum = p.pnum)
+
+select
+(select grade from mark where deptcode = c1.deptcode and cnum = c1.cnum and term = c1.term and section = c1.section order by grade desc limit 1)
+,
+(select grade from mark where deptcode = c1.deptcode and cnum = c1.cnum and term = c1.term and section = c1.section order by grade asc limit 1)
+,
+(select grade from mark where deptcode = c2.deptcode and cnum = c2.cnum and term = c2.term and section = c2.section order by grade desc limit 1)
+,
+(select grade from mark where deptcode = c2.deptcode and cnum = c2.cnum and term = c2.term and section = c2.section order by grade asc limit 1),
+c1.cnum, c1.term, c1.pnum, c1.pname, c1.deptcode, c1.section, c1.pnum,
+c2.cnum, c2.term, c2.pnum, c2.pname, c2.deptcode, c2.section, c2.pnum
+from combineTable c1, combineTable c2
+where c1.term = c2.term and c1.deptcode = c2.deptcode and c1.cnum = c2.cnum and c1.pnum != c2.pnum;
+
+/*
+Pairs of distinct professors such that whenever the first one teaches a class
+in a particular term the second also teaches a class for the same course
+in the same term. Report a professor number and name for both the
+professors.
+*/
+select p1.pnum, p1.pname, p2.pnum, p2.pname from professor p1, professor p2
+ where p1.pnum != p2.pnum and not exists
+ (
+  select * from class c, class c2 where
+    c.pnum = p1.pnum and c2.pnum = p2.pnum and (
+    c.deptcode != c2.deptcode or
+    c.term != c2.term or
+    c.cnum != c2.cnum)
+ );
+-- NOW CAN USE AGGREGATION
+
+/*
+The course number and total enrollment count for all of its classes of each
+course. Also, include only those course numbers for courses with a total
+enrollment count among the three lowest such counts.
+*/
+-- Not sure if this will return an error, or 3 rows per old.deptcode, old.cnum since the 3rd parameter (the subquery) has 3 rows
+-- didn't break running on an empty dataset
+select old.deptcode, old.cnum, (select count(*) from enrollment where deptcode = old.deptcode and cnum = old.cnum group by deptcode, cnum order by count(*) asc limit 3) from class old;
+
+/*
+The percentage of professors in pure math who have always taught no
+more than a single course in any given term. (Note that a percentage
+should be a number between 0 and 100.)
+*/
+select count(*) from professor p where deptcode = 'PM' and pnum in
+(
+  select c.pnum from class c where c.pnum = p.pnum and c.pnum not in
+  (
+    select c1.pnum from class c1 where pnum = p.pnum and c1.term = c.term and (c1.deptcode != c.deptcode or c1.cnum != c.cnum)
+  )
+)
+/ (select count(*) from professor where deptcode = 'PM');
+
+/*
+The number of different third or fourth year students in each section of
+each course taught by a pure math professor in past terms. The result
+should include the professor number, professor name, course number and
+section, and should also be sorted first by the name of the professor,
+then by the professor number, third by the course number, and finally by
+section. (Note that a section is identified by a term and a section number.
+Also assume that sorting by section means sorting by term and then by
+section number. The result will therefore have a total of six columns.)
+*/
+-- ran on empty dataset
+select (select pname from professor where pnum = c.pnum), c.pnum, c.cnum, c.term, c.section,
+  (select count(distinct snum) from mark where snum in
+  (
+    select snum from student where year between 3 and 4
+  ) and deptcode = c.deptcode and cnum = c.cnum and term = c.term and section = c.section)
+from class c where pnum in
+(
+  select pnum from professor where deptcode = 'PM'
+) and term != 1185;
+
+/*
+The ratio of professors in pure math (PM) to professors in applied math
+(AM) who have taught a class in which the average grade obtained in the
+class was greater than 77.
+*/
+select count(*) from professor p where deptcode = 'PM' and pnum in
+(
+  (select c.pnum from class c where
+  (
+    select avg(grade) from mark where c.deptcode = deptcode and c.cnum = cnum and c.term = term and c.section = section
+  ) > 77)
+)
+/
+(select count(*) from professor p where deptcode = 'AM' and pnum in
+(
+  select c.pnum from class c where
+  (
+    select avg(grade) from mark where c.deptcode = deptcode and c.cnum = cnum and c.term = term and c.section = section
+  ) > 77
+));
+
+/*
+For the current term, report how many courses there are in the schedule
+with a particular number of classes. For example an output
+{[5, 1], [4, 2], [1, 5]}
+indicates that there are 5 courses with a single class (section), 4 courses
+with 2 classes, and 1 course with 5 classes scheduled in the curent term.
+*/
+-- ran on empty dataset
+with eachclass (sectioncount) as
+(select count(*) from class
+  where term = 1185
+  group by (deptcode, cnum))
+select count(*), sectioncount from eachclass group by sectioncount;

a2/test.sql

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+-- run this to use test: db2 -tvmf test.sql
+with eachclass (sectioncount) as
+(select count(*) from class
+  where term = 1185
+  group by (deptcode, cnum))
+select count(*), sectioncount from eachclass group by sectioncount;