Sql query question - been trying for two days

Question

Hi guys im trying to carry out an sql query
Im using a left join to do a query, which gives me a set of results:
select COURSESTUDENT.StudentNo, COURSESTUDENT.CourseCode, COURSESTUDENT.Year, MARKS.ExamMark, MARKS.EntryNo FROM COURSESTUDENT LEFT JOIN MARKS ON COURSESTUDENT.StudentNo=MARKS.StudentNo AND COURSESTUDENT.CourseCode=MARKS.CourseCode AND COURSESTUDENT.Year=MARKS.Year
but I would like to do a select on this result but do not want to use a create view as if more than one person access this page at a time then if the servlet tries to create the view an error will occur.
I would like to do the following select statement on the results of the query above..
select * from (above) where CourseCode='ELE304' AND Year=1999;
Is this possible, im using postgres..
Please help......
thanks
tzaf

Answer 1

Sorry, I have never used postgres, but in several databases, the following syntax would work and provide the correct ResultSet.
select *
from (
     SELECT
         COURSESTUDENT.StudentNo,
         COURSESTUDENT.CourseCode,
         COURSESTUDENT.Year,
         MARKS.ExamMark,
         MARKS.EntryNo
     FROM
         COURSESTUDENT LEFT JOIN MARKS ON
         COURSESTUDENT.StudentNo=MARKS.StudentNo AND
         COURSESTUDENT.CourseCode=MARKS.CourseCode AND 
         COURSESTUDENT.Year=MARKS.Year
     ) A
WHERE
    CourseCode='ELE304' AND
    Year=1999