Posted by Dave Smithz on 01/23/06 00:10

Thanks for the input.
> OK so you want to subvert the normalization your database. This is
> marginally more acceptable than cross-posting.
Did not understand the first sentence. Is this a good or bad thing?
> So that rules out subselects.
Yes it is annoying that I have to support MySQL 3

>
>
> Messy if you only want to find out whom has not attended:
>
> SELECT a.student_id
> FROM students a LEFT JOIN studentclasslink b
> ON a.student_id=b.student_id
> HAVING b.student_id IS NULL

Good point in finding how many members have not attended. The SQL I gave was
to more demonstrate my problem. Even with the above code, I still do not
know how I apply this to an update situation.
My worse case scenario is to in the PHP code store the row id's of the rows
that need to be updated. But I was thinking there should be an SQL method.

> As to what you do next - I guess you already know that since you posted to
> comp.lang.php (amongst others)

Not wanting to get away from the main pont, I only posted into two related
groups. Sometimes it is not clear to which group to post. I do not see why
it is such a problem cross posting if the groups are carefully selected and
relevant. Maybe it is the Newsreader I use does not make it a problem, and
maybe I will now hear otherwise, but what really is the big problem with the
occasional cross posting on groups that are related. Surely it is better
then posting the same message twice into each group but at different times.

Kind regards

Dave

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