Query to Find the Student ids by group

Question

Hi,
I have a table which has 2 columns student_id and Course_id.
Sample Data
Student_id Course_id
1 -->     1
1 -->     2
1 -->     3
1 -->     4
2 -->     1
2 -->     3
3 -->     1
3 -->     2
3 -->     4
I want to find those students who have taken all the courses 1,3,4.

Answer 1

952541 wrote:
I want to find those students who have taken all the courses 1,3,4.Depends on:
a) Can student take same course more than once?
a) Only courses 1,3,4 and no other courses?
1. Student can't take same course more than once and student took courses 1,3,4 and may be some other courses:
select  stu_id
  from  t
  where stu_curs in (1,3,4)
  group by stu_id
  having count(stu_curs) = 3
/2. Student can take same course more than once and student took courses 1,3,4 and may be some other courses:
select  stu_id
  from  t
  where stu_curs in (1,3,4)
  group by stu_id
  having count(distinct stu_curs) = 3
/3. Student can't take same course more than once and student took courses 1,3,4 and no other courses:
select  stu_id
  from  t
  group by stu_id
  having sum(case when stu_curs in (1,3,4) then stu_curs else 10 end) = 8
/2. Student can take same course more than once and student took courses 1,3,4 and no other courses:
select  stu_id
  from  t
  group by stu_id
  having sum(distinct case when stu_curs in (1,3,4) then stu_curs else 10 end) = 8
/SY.