How to do a Nested Query ?

Question

I have three Tables Student, Courses, Marks
Table : Student
Columns
StudentID <PK>
First Name
Last Name
Table : Grades
Columns
StudentID <FK>
Grade
Table : Courses
Columns
StudentID <FK>
CourseID
CourseDesc
Now to get all the course descriptions which this particular student is taking based on the StudentID we do something like this :
SELECT c.courseDesc
FROM Courses c, Student s
WHERE s.StudentID = '100'
AND s.StudentID = c.StudentID
The above will work
But If I need to do it in nested query how can I do it : Something like
SELECT * FROM
SELECT c.courseDesc
FROM Courses c, Student s
AND s.StudentID = c.StudentID
WHERE s.StudentID = '100'
Thanks for the help.
Harsimrat

Answer 1

oops,try this...
SELECT * FROM (
SELECT s.StudentID,c.courseDesc
FROM Courses c, Student s
WHERE s.StudentID = c.StudentID)
WHERE StudentID = '100';
SQL> select * from
  2  (select e.ename,d.deptno from test_dept d,test_emp e where e.deptno = d.deptno)
  3  where deptno = 10;
ENAME          DEPTNO
BLAKE              10
CLARK              10
KING               10
MILLER             10
SQL>