> > Use the SQL92 JOIN syntax:
> > FROM student_selection s JOIN student_biodata b
> > ON (s.student_id=b.student_id)
>
>I've tried this, but it can NOT exclude students who already selected in
>another school on higher priority. Can you give more hints ?

This is exactly the same as your original query which contained

FROM student_selection s, student_biodata b
WHERE s.student_id=b.student_id

excepting that using SQL92 makes it easier for your tool to decide which
plan to use (e.g. if you use IBO, then your way of writing makes it
important to fill in JoinLinks correctly, whereas Martijn can simply forget
this property). Following Martijns suggestion doesn't change the output of
your query in any way, it is just a good advice to follow.

By the way, I've tried to change the subject of this query, it may still
mess up some readers, but at least it will be possible to read out of the
title which replies belong to your question and which belong to Louis.

Set