Consider the following relations:
Student(ID, course, sec, semester, year)
Teacher(TID, course, sec, semester, year, salary)
What is the query to find the total number of (distinct) students who have taken courses taught by the instructor with ID 100?
1
select distinct ID
from Student
where (course, sec, semester, year) in (select course, sec, semester, year
from Teacher where Teacher.TID= 100);
2
select course, sec, semester, year
from Teacher where Teacher.TID= 100;
3
select count (distinct ID)
from Student
where (course, sec, semester, year) in (select course, sec, semester, year
from Teacher where Teacher.TID= 100);
4
select course, sec, semester, year
from Student where (select course, sec, semester, year
from Teacher where Teacher.TID= 100);