Thank you Chris.

I agree with you wholeheartedly that the SQL should be optimized.
Now, I don't want to freeload on your time, but I have a very complex query,
which I have been pondering over for the last many days.
If anyone can tell me what query will return just one row for the problem I
have, s/he will be SQL Guru to me.

My problem is:
I have 3 tables (given below). A member of the staff takes courses and for
each course he has requirement id, these details get stored in the
staff_courses table. Each course taken will have a requirement specification
which could be any of 4 values given below (after the reqs table). I need to
get totals for each requirement for each member of the staff. I am using
MySQL (and cannot use sub-queries). I have been able to get the requirement
totals for each member using Group By reqid, but I get a separate row for
each requirement against the member of staff. So if a member has taken 3
courses, and one course has a reqid of 0 and the other two courses have a
reqid of 1, I get 2 rows in the result set for that staffid, one will
contain the reqid 0 and total as 1, while the second row will contain the
reqid as 1 and the total as 2.

Can I get the totals for each requirement in one row and can I do this in
one query?

1)"staff" table

2)"staff_courses" table

3)"reqs" table

contains the
reqid  requirement
0 No action
1 Primary requirement
2 Further requirement
3 Completed

-----Original Message-----
t]On Behalf Of Chris Hewitt
Sent: Tuesday, September 24, 2002 1:49 PM
Subject: Re: [PHP] in a logic loop!

Naintara Jain wrote:

>What I am doing is:
>I maintain a set of details in say $prev_row (previous row) and another in
>cur_row (current row).
>The minute my cur_row detail (one unique id) doesn't match the prev_row
>detail, I print out all the previous row details, and reinitialize the
>various variables (all in a loop).
>This works fine for all cases but fails for the last ID, because of the
>logic used. Do I need to create a special case for the last one, or can
>anyone suggest a better way?
When you come out of your loop, either there will be one row left to
print, or there were no matching rows. Suggestion one is to test for
this and if there were matching rows, do a special case for the last row.

Alternatively, you are printing a row when the ID changes, that is, the
last row of the 1 to 3 matching rows. Why not print the first one, not
last one? You change the logic
to print the first row then ignore others with the same ID. It could be
that (because of an Order By clause) the last row is the correct one and
the data may differ between rows with the same ID.

You say you do not want to do it in the SQL statement itself, but this
really is the right place. If MySQL use a LIMIT clause to only get one
row, if you cannot refine the SQL statement to only retrieve one row.


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