Question

I have the following table and I want to retrieve students (STUD_ID) who have taken either ENGLISH or SCIENCE. If they have taken both ENGLISH and SCIENCE, then do not retrieve.

So the desired output is 101,102,104,106,107

The table is actually a View with the first 2 columns from the table STUD_INFO and the subject column are from a Nested table within the STUD_INFO table.

SELECT groupid, 
       Stud_id, 
       NST.Name
  FROM STUD_INFO, 
       TABLE(SUBINFO) NST

Can anyone help me with a SQL query? The interesting part is when I use
Subject = ENGLISH and Subject = Science it does not retrieve any data.

groupid Stud_id Subject
-------   -------   --------
1   101 ENGLISH
1   102 MATH
1   103 ENGLISH
1   103 SCIENCE
1   104 ENGLISH
1   104 MATH
1   105 PT
1   105 ENGLISH
1   105 SCIENCE
2   106 ENGLISH
2   107 SCIENCE
2   108 SCIENCE
2   108 ENGLISH

Answer 1

Subject = ENGLISH and Subject = SCIENCE says “Subject needs to be both ENGLISH and SCIENCE at the same time” which can never be true.

select stud_id from your_view
where subject in ('ENGLISH', 'SCIENCE')
group by stud_id
having count(subject) = 1

Does this work for you?