Rozenshtein question 10(sql cookbook)

all students only taking 2 particular courses  - a cleaner approach IMHO

select s.sno,s.sname,

sum(case  when  t.cno in('CS112', 'CS114') then 1 else 0 end)

from student s inner join take t on  t.sno = s.sno

group by s.sno,s.sname

having sum(case when  t.cno in('CS112', 'CS114') then 1 else 0 end) = 2

and  count(*) = 2